SH7641 Datasheet, PDF (522/1036 Pages) Renesas Technology Corp – Renesas 32-Bit RISC Microcomputer SuperH™ RISC engine Family / SH7641 Series

Section 15 User Debugging Interface (H-UDI)
EXTEST: This instruction is provided to test external circuitry when the this LSI is mounted on a
printed circuit board. When this instruction is executed, output pins are used to output test data
(previously set by the SAMPLE/PRELOAD instruction) from the boundary scan register to the
printed circuit board, and input pins are used to latch test results into the boundary scan register
from the printed circuit board. If testing is carried out by using the EXTEST instruction N times,
the Nth test data is scanned-in when test data (N-1) is scanned out.
Data loaded into the output pin boundary scan register in the Capture-DR state is not used for
external circuit testing (it is replaced by a shift operation).
The upper four bits of the instruction code are B'0000.
IDCODE: A command can be set in SDIR by the H-UDI pins to place the H-UDI pins in the
IDCODE mode stipulated by JTAG. When the H-UDI is initialized (TRST is asserted or TAP is in
the Test-Logic-Reset state), the IDCODE mode is entered.
CLAMP, HIGHZ: A command can be set in SDIR by the H-UDI pins to place the H-UDI pins in
the CLAMP or HIGHZ mode stipulated by JTAG.
15.5.2 Points for Attention
1. Boundary scan mode does not cover clock-related signals (EXTAL, XTAL, CKIO, CKIO2).
2. Boundary scan mode does not cover reset-related signals (RESETP, RESETM).
3. Boundary scan mode does not cover H-UDI-related signals (TCK, TDI, TDO, TMS, TRST).
4. The USB-transceiver-related signals (DP, DM) are beyond the scope of the boundary scan.
5. When the EXTEST, CLAMP, and HIGHZ commands are set, fix the RESETP pin low.
6. When a boundary scan test for other than BYPASS and IDCODE is carried out, fix the
ASEMD0 pin high.
15.6 Usage Notes
1. An H-UDI command, once set, will not be modified as long as another command is not re-
issued from the H-UDI. If the same command is given continuously, the command must be set
after a command (BYPASS, etc.) that does not affect chip operations is once set.
2. H-UDI commands are not accepted in standby mode, since operation of the LSI is suspended. To retain
the TAP status before and after standby mode, keep TCK high before entering standby mode.
3. The H-UDI is used for emulator connection. Therefore, H-UDI functions cannot be used when
using an emulator.
Rev. 4.00 Sep. 14, 2005 Page 472 of 982
REJ09B0023-0400