tmp19a44fda TOSHIBA Semiconductor CORPORATION, tmp19a44fda Datasheet - Page 584

• Manufacturer Part Number: tmp19a44fda
• Description: 32bit Tx System Risc
• Manufacturer: TOSHIBA Semiconductor CORPORATION

JTAG Interface
23.4.2
The SAMPLE and PRELOAD instructions are used to connect TDI and TDO by way of the boundary
scan register.
Each instruction performs the function described below:
•
•
Input
Input
TDI
TDI
SAMPLE and PRELOAD Instructions
The SAMPLE instruction is used to monitor the I/O pad of an IC. While SAMPLE is monitoring
the I/O pads, the internal logic is not disconnected from the I/O pins of an IC. This instruction is
executed in the Capture-DR state. A main function of SAMPLE is to read values of the I/O pins
of an IC at the rising edge of TCK during normal functional operation. Fig. 23-9 shows the flow
of data while the SAMPLE instruction is selected.
The PRELOAD instruction is used to initialize the boundary scan register before selecting other
instructions. For example, the boundary scan register is initialized using PRELOAD before
selecting the EXTEST instruction, as previously explained. PRELOAD shifts data into the
boundary scan register without affecting the normal operation of the system logic. Fig. 23-10
shows the flow of data while the PRELOAD instruction is selected.
Fig. 23-10 Flow of Test Data While PRELOAD Is Selected
Fig. 23-9 Flow of Data While SAMPLE Is Selected
TMP19A44(rev1.3) 23-12
Boundary scan path
Boundary scan path
Internal logic
Internal logic
TMP19A44
Output
Output
TDO
TDO
2010-04-01