Renesas SH7781 用户手册

30.   User Debugging Interface (H-UDI) 

Rev.1.00  Jan. 10, 2008  Page 1503 of 1658 

REJ09B0261-0100 

 

In the H-UDI in this LSI, the boundary-scan TAP controller is separated from the TAP controller 
for other H-UDI function control. When the 

TRST is asserted (including when the power is turned 

on), the boundary-scan TAP controller operates and the boundary scan function specified in JTAG 
can be used. By inputting the switching command, an H-UDI reset and H-UDI interrupts can be 
used. However, the following restrictions are put on this LSI. 

•  Clock-related pins (EXTAL and XTAL) are out of the scope of the boundary scan test. 
•  Reset-related pin (PRESET) is out of the scope of the boundary scan test. 
•  H-UDI-related pins (TCK, TDI, TDO, TMS, TRST, AUDSYNC, AUDCK, AUDATA3 to 

AUDATA0, and MPMD) are out of the scope of the boundary scan test. 

•  DDRIF-related pins are out of the scope of the boundary scan test. 
•  During the boundary scan (IDCODE, EXTEST, SAMPLE/PRELOAD, BYPASS, and H-UDI 

switching command), the maximum frequency of TCK is 10 MHz. 

•  The access size from the H-UDI to the boundary-scan TAP controller is 8 bits. 

 

The commands supported by the boundary-scan TAP controller are shown below. 

Note:  During the boundary scan, the MPMD and the 

PRESET pins should be fixed to high level. 

When the H-UDI operates in emulation support mode (MPMD = 0), the boundary scan 
function cannot be used. Figure 30.2 shows the sequence to switch from the boundary-
scan TAP controller to the H-UDI. 

0 1 0 1 0 1 0 1 IDCODE 

1 1 1 1 1 1 1 1 BYPASS 

0 0 0 0 0 0 0 0 EXTEST 

0 1 0 0 0 0 0 0 SAMPLE/PRELOAD 

0 0 0 0 1 0 0 0 H-UDI 

switching 

command 

Other than above 

Setting prohibited