SH7670 Datasheet, PDF (1117/1292 Pages) Renesas Technology Corp – 32-Bit RISC Microcomputer SuperHTM RISC engine Family / SH7670 Series

Section 26 High-Performance User Debugging Interface (H-UDI)
26.5 Usage Notes
1. An H-UDI command, once set, will not be modified as long as another command is not set
again from the H-UDI. If the same command is to be set continuously, the command must be
set after a command (BYPASS mode, etc.) that does not affect chip operations is once set.
2. In software standby mode and H-UDI module standby state, all of the functions in the H-UDI
cannot be used. To retain the TAP status before and after standby mode, keep TCK high before
entering standby mode.
3. Regardless of whether the H-UDI is used, make sure to keep the TRST pin low at power-on to
initialize the H-UDI.
4. Make sure to put 20 t_cyc or more between the signal change timing of the RES and TRST pins.
5. When starting the TAP controller after the negation of the TRST pin, make sure to allow 200
ns or more after the negation.
Rev. 1.00 Nov. 14, 2007 Page 1091 of 1262
REJ09B0437-0100