EP0417905A2
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EP
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System scan path architecture
Assignee: Texas Instruments Inc
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Filing: 1990-08-08
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Granted: —
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Expires: 2010-08-08
Abstract
Abstract A system scan path architecture is provided by a device select module (DSM) (18) which may be used in conjunction with associated circuits (16a-b) to select secondary scan paths (PATH1-m) on each circuit for coupling with a primary scan path on a test bus (14). The test bus (14) is controlled by a primary bus master (12). Remote bus masters may be used in conjunction with the DSMs (18) to provide serial-scan testing independent of the primary bus master (12).
Inventors
- 👤 Lee D. Whetsel
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-11-06 16:19
CPC Classifications
G; G06; G06F; G06F11/00; G06F11/22; G06F11/2294; G01; G01R; G01R31/00; G01R31/28; G01R31/317; G01R31/3181; G01R31/3185; G01R31/318533; G01R31/318558; G06F2201/00; G06F2201/88
Claims Analysis
Total Claims: 43
Claim 1
Independent Claim
97 words
Circuitry for performing serial-scan testing on a plurality of predefined circuits, each having a plurality of secondary scan paths, comprising: a test bus comprising control and data signal lines connected to the predefined circuits; a test bus controller for transmitting and receiving signals to and from the predefined circuits on said bus; and device select modules connected to respective predefined circuits and responsive to said control and data lines for selectively coupling secondary scan paths onto a primary scan path such that the length of the scan path may be optimized for a desired serial-scan test operation.
Claim 2
Dependent Claim
97 words
Circuitry for performing serial-scan testing on a plurality of predefined circuits, each having a plurality of secondary scan paths, comprising: a test bus comprising control and data signal lines connected to the predefined circuits; a test bus controller for transmitting and receiving signals to and from the predefined circuits on said bus; and device select modules connected to respective predefined circuits and responsive to said control and data lines for selectively coupling secondary scan paths onto a primary scan path such that the length of the scan path may be optimized for a desired serial-scan test operation.
Claim 3
Dependent Claim
38 words
The circuitry of Claim 1 wherein said test bus controller comprises processor circuitry for transmitting control and data signals on said test bus to select a desired secondary scan path to be coupled to said primary scan paths.
Claim 4
Dependent Claim
28 words
The circuitry of Claim 1 wherein each of said device select modules include a primary test port for receiving control and data signals from the test bus controller.
Claim 5
Dependent Claim
114 words
Circuitry for performing serial-scan testing on a plurality of predefined circuits, each predefined circuit having a plurality of secondary scan paths, comprising: a test bus for coupling control and data signals to the circuits; a test bus controller for transmitting and receiving signals to and from the circuits on said bus; primary device select modules connected to respective circuits and responsive to said control lines for selectively coupling secondary scan paths to a primary scan path; and secondary device select modules coupled to said primary device select modules, each of said secondary device select modules operable to selectively couple associated secondary scan paths to the primary scan path via said primary device select modules.
Claim 6
Dependent Claim
114 words
Circuitry for performing serial-scan testing on a plurality of predefined circuits, each predefined circuit having a plurality of secondary scan paths, comprising: a test bus for coupling control and data signals to the circuits; a test bus controller for transmitting and receiving signals to and from the circuits on said bus; primary device select modules connected to respective circuits and responsive to said control lines for selectively coupling secondary scan paths to a primary scan path; and secondary device select modules coupled to said primary device select modules, each of said secondary device select modules operable to selectively couple associated secondary scan paths to the primary scan path via said primary device select modules.
Claim 7
Dependent Claim
20 words
The circuitry of Claim 4 said control signals are routed in parallel to each of the primary device select modules.
Claim 8
Dependent Claim
22 words
The circuitry of Claim 4 wherein the control signals are routed directly to each secondary device select module to minimize propagation delays.
Claim 9
Dependent Claim
36 words
The circuitry of Claim 4 and wherein each of said primary and secondary device select modules include a data register for receiving data from said test bus responsive to control signal received from said test sport.
Claim 10
Independent Claim
68 words
A method of performing serial-scan testing on a plurality of predefined circuits, each predefined circuit having a plurality of secondary scan paths, comprising the steps of: sending and receiving control and data signals on a test bus; and selectively coupling ones of the secondary scan paths to a primary scan path such that the length of the scan path may be optimized for a desired serial-scan test operation.
Claim 11
Independent Claim
68 words
A method of performing serial-scan testing on a plurality of predefined circuits, each predefined circuit having a plurality of secondary scan paths, comprising the steps of: sending and receiving control and data signals on a test bus; and selectively coupling ones of the secondary scan paths to a primary scan path such that the length of the scan path may be optimized for a desired serial-scan test operation.
Claim 12
Dependent Claim
32 words
The method of Claim 8 and further comprising the step of selectively storing control and data signals from said test bus in a data register associated with one of the predefined circuits.
Claim 13
Dependent Claim
105 words
Circuitry for performing serial-scan testing of a plurality of circuits, each predefined circuit having a plurality of secondary scan paths, comprising: a primary bus for carrying control and data signals to the circuits; a primary bus controller for transmitting signals to and receiving signals from said bus; a device select module associated with one of said predefined circuits for selectively coupling one of said secondary scan paths associated with said one predefined circuit to a primary scan path; and a remote bus controller associated with said device select module operable to perform serial-scan testing on said associated predefined circuit independent of said primary bus controller.
Claim 14
Dependent Claim
105 words
Circuitry for performing serial-scan testing of a plurality of circuits, each predefined circuit having a plurality of secondary scan paths, comprising: a primary bus for carrying control and data signals to the circuits; a primary bus controller for transmitting signals to and receiving signals from said bus; a device select module associated with one of said predefined circuits for selectively coupling one of said secondary scan paths associated with said one predefined circuit to a primary scan path; and a remote bus controller associated with said device select module operable to perform serial-scan testing on said associated predefined circuit independent of said primary bus controller.
Claim 15
Dependent Claim
21 words
The circuitry of Claim 10 and further comprising a parallel bus coupling said remote bus controller to said device select module.
Claim 16
Dependent Claim
46 words
The circuitry of Claim 10 wherein said remote bus controller comprises: a processor to execute test programs; a memory to store said test programs; input/output circuitry for reading and writing data to said parallel bus; and a test bus controller for transmitting and receiving serial data.
Claim 17
Dependent Claim
37 words
The circuitry of Claim 11 and further comprising tristate devices associated with said remote bus controller and said device select module to selectively decouple said remote bus controller or said device select module from said parallel bus.
Claim 18
Dependent Claim
52 words
The circuitry of Claim 13 and further comprising pullup and pull-down resistors connected between said parallel bus and respective predetermined voltages such that an identifying code may be placed on said parallel bus during periods when neither the remote bus controller the device select module is outputting data to the parallel bus.
Claim 19
Dependent Claim
26 words
The circuitry of Claim 10 wherein said device select module includes a primary test port for receiving control and data signals from the primary bus controller.
Claim 20
Dependent Claim
76 words
Circuitry for performing serial-scan testing of a plurality of predefined circuits, each predefined circuit including a plurality of secondary scan paths, comprising: a primary bus carrying control and data signals and defining a primary scan path: a primary bus controller for transmitting signals to and receiving signals from said bus to perform scan test operations; and a remote bus controller for selectively controlling an associated predefined circuit responsive to control signals from said primary bus controller.
Claim 21
Dependent Claim
76 words
Circuitry for performing serial-scan testing of a plurality of predefined circuits, each predefined circuit including a plurality of secondary scan paths, comprising: a primary bus carrying control and data signals and defining a primary scan path: a primary bus controller for transmitting signals to and receiving signals from said bus to perform scan test operations; and a remote bus controller for selectively controlling an associated predefined circuit responsive to control signals from said primary bus controller.
Claim 22
Dependent Claim
28 words
The circuitry of Claim 16 and further comprising a bidirectional bus coupled to said primary and remote bus controllers and operable to provide communications between said bus controllers.
Claim 23
Dependent Claim
59 words
The circuitry of Claim 17 and further comprising a device select module coupled to said bidirectional bus and said primary controller, said device select module operable to convert serial data from said primary bus controller to parallel data for the bidirectional bus and to convert parallel data from said bidirectional bus to serial data for said primary bus controller.
Claim 24
Independent Claim
108 words
A method of communicating from a primary bus controller coupled to a plurality of predefined circuits to one of a plurality of respective remote bus controllers associated with said predefined circuits, the remote bus controllers being operable to perform serial-scan testing on the respective predefined circuits, comprising the steps of: receiving an interrupt from the primary bus controller; inputting a data pattern from the primary bus controllers in response to said interrupt; identifying the data pattern; transmitting an acknowledge signal to the primary bus controller if the DATA PATTERN is header command; and receiving additional data patterns from the primary bus controller in response to the acknowledge signal.
Claim 25
Independent Claim
108 words
A method of communicating from a primary bus controller coupled to a plurality of predefined circuits to one of a plurality of respective remote bus controllers associated with said predefined circuits, the remote bus controllers being operable to perform serial-scan testing on the respective predefined circuits, comprising the steps of: receiving an interrupt from the primary bus controller; inputting a data pattern from the primary bus controllers in response to said interrupt; identifying the data pattern; transmitting an acknowledge signal to the primary bus controller if the DATA PATTERN is header command; and receiving additional data patterns from the primary bus controller in response to the acknowledge signal.
Claim 26
Dependent Claim
29 words
The method of Claim 19 and further comprising the step of receiving a stop command to the remote bus controller to indicate the end of the data pattern sequence.
Claim 27
Dependent Claim
37 words
The method of Claim 19 and wherein the step of inputting the data pattern comprises the step of receiving a data pattern from a device select module coupled to the remote bus controller via a parallel bus.
Claim 28
Dependent Claim
32 words
The method of Claim 19 and further comprising the step of receiving an acknowledge signal from the primary bus controller in response to the acknowledge signal sent to the primary bus controller.
Claim 29
Dependent Claim
31 words
The method of Claim 19 and further comprising the step of receiving a count pattern indicating the number of additional data patterns which will be sent by the primary bus controller.
Claim 30
Dependent Claim
23 words
The method of Claim 19 and further comprising the step of performing a test on said respective circuit in response to the commands.
Claim 31
Dependent Claim
110 words
Circuitry for communicating from a primary bus controller coupled to a plurality of predefined circuits to one of a plurality of respective remote bus controllers associated with said predefined circuits, the remote bus controllers being operable to perform serial-scan testing on the respective predefined circuits, comprising: circuitry for receiving an interrupt from the primary bus controllers; circuitry for receiving a data pattern from the primary bus controllers; circuitry for identifying the data pattern; circuitry for transmitting an acknowledge signal to the primary bus controller if the data pattern is a header command; and circuitry for receiving additional data patterns from the primary bus controller in response to the acknowledge signal.
Claim 32
Dependent Claim
110 words
Circuitry for communicating from a primary bus controller coupled to a plurality of predefined circuits to one of a plurality of respective remote bus controllers associated with said predefined circuits, the remote bus controllers being operable to perform serial-scan testing on the respective predefined circuits, comprising: circuitry for receiving an interrupt from the primary bus controllers; circuitry for receiving a data pattern from the primary bus controllers; circuitry for identifying the data pattern; circuitry for transmitting an acknowledge signal to the primary bus controller if the data pattern is a header command; and circuitry for receiving additional data patterns from the primary bus controller in response to the acknowledge signal.
Claim 33
Dependent Claim
29 words
The circuitry of Claim 25 and further comprising circuitry for receiving a stop data pattern to the remote bus controller to indicate the end of the data pattern sequence.
Claim 34
Dependent Claim
35 words
The circuitry of Claim 25 wherein said circuitry for receiving the data pattern comprises circuitry for receiving a data pattern from a device select module coupled to the remote bus controller via a parallel bus.
Claim 35
Independent Claim
109 words
A method of communicating to a primary bus controller coupled to a plurality of predefined circuits from one of a plurality of respective remote bus controllers associated with said predefined circuits, the remote bus controllers being operable to perform serial-scan testing on the respective predefined circuits, comprising the steps of: receiving an interrupt from the remote bus controllers; inputting a data pattern from the remote bus controllers in response to said interrupt; identifying the data pattern; transmitting an acknowledge signal to the remote bus controller if the data pattern is a header command; and receiving additional data patterns from the remote bus controller in response to the acknowledge signal.
Claim 36
Independent Claim
109 words
A method of communicating to a primary bus controller coupled to a plurality of predefined circuits from one of a plurality of respective remote bus controllers associated with said predefined circuits, the remote bus controllers being operable to perform serial-scan testing on the respective predefined circuits, comprising the steps of: receiving an interrupt from the remote bus controllers; inputting a data pattern from the remote bus controllers in response to said interrupt; identifying the data pattern; transmitting an acknowledge signal to the remote bus controller if the data pattern is a header command; and receiving additional data patterns from the remote bus controller in response to the acknowledge signal.
Claim 37
Dependent Claim
29 words
The method of Claim 28 and further comprising the step of receiving a stop command from the remote bus controller to indicate the end of the data pattern sequence.
Claim 38
Dependent Claim
37 words
The method of Claim 28 and wherein the step of inputting the data pattern comprises the step of receiving a data pattern via a device select module coupled to the remote bus controller via a parallel bus.
Claim 39
Dependent Claim
105 words
Circuitry for communicating to a primary bus controller coupled to a plurality of predefined circuits from one of a plurality of respective remote bus controllers associated with said predefined circuits, the remote bus controllers being operable to perform serial-scan testing on the respective predefined circuits, comprising: circuitry for receiving an interrupt from the remote bus controller: circuitry for receiving a data pattern from the remote bus controller; circuitry for identifying the data pattern; circuitry for transmitting an acknowledge signal if the data pattern is a header command; and circuitry for receiving additional data patterns from the remote bus controller in response to the acknowledge signal.
Claim 40
Dependent Claim
105 words
Circuitry for communicating to a primary bus controller coupled to a plurality of predefined circuits from one of a plurality of respective remote bus controllers associated with said predefined circuits, the remote bus controllers being operable to perform serial-scan testing on the respective predefined circuits, comprising: circuitry for receiving an interrupt from the remote bus controller: circuitry for receiving a data pattern from the remote bus controller; circuitry for identifying the data pattern; circuitry for transmitting an acknowledge signal if the data pattern is a header command; and circuitry for receiving additional data patterns from the remote bus controller in response to the acknowledge signal.
Claim 41
Dependent Claim
28 words
The circuitry of Claim 31 and further comprising circuitry for receiving a stop command from the remote bus controller to indicate the end of the data pattern sequence.
Claim 42
Dependent Claim
35 words
The circuitry of Claim 31 wherein said circuitry for receiving the data pattern comprises circuitry for receiving a data pattern from a device select module coupled to the remote bus controller via a parallel bus.
Claim 43
Dependent Claim
35 words
The circuitry of Claim 33 wherein said circuitry for identifying the data pattern comprises circuitry for comparing the signals on the parallel bus to a unique predetermined identification code associated with the remote bus controller.
References Cited (Backward Citations)
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