HD6417751 Datasheet, PDF (840/1105 Pages) Renesas Technology Corp – SuperH RISC engine

21.3.4 Boundary Scan (EXTEST, SAMPLE/PRELOAD, BYPASS)
The H-UDI pin can be set in the JTAG boundary scan mode by setting a command in SDIR from
the H-UDI. However, in the case of the SH7751 Series, the bypass register (SDBPR) is not
initialized in the Capture-DR state, and the following limitations apply:
1. Clock-related signals (EXTAL, EXTAL2, XTAL, XTAL2, and CKIO) are excluded from the
boundary scan.
2. Reset-related signals (5(6(7, 05(6(7, and CA) are excluded from the boundary scan.
3. H-UDI signals (TCK, TDI, TDO, TMS, and 7567) are excluded from the boundary scan.
4. With EXTEST, assert the 05(6(7 pin (Low), negate the 5(6(7 pin (High), and assert the
CA pin (High). With SAMPLE/PRELOAD, assert the CA pin (High).
5. When executing a boundary scan (EXTEST, SAMPLE/PRELOAD, and BYPASS), supply a
clock signal to the EXTAL pin. The allowed range of input clock frequencies is from 1 to 33.3
MHz. Execute the boundary scan after t_OSC1 (the power-on oscillation-stabilization time) has
elapsed. The clock signal need not be supplied to the EXTAL pin after t_OSC1 has elapsed. For
details on t_OSC1 (the power-on oscillation-stabilization time), see section 23, Electrical
Characteristics.
6. When the SH7751 is in bypass mode, the bypass register (SDBPR) is not fixed in the Capture-
DR state. (It is cleared to 0 in the SH7751R.)
21.4 Usage Notes
1. SDIR Command
Once an SDIR command is set, it does not change until another command is written from the
H-UDI, unless initialized by asserting 7567 or the TAP is set in the Test-Logic-Reset state.
2. SDIR Commands in Sleep Mode
Sleep mode is cleared by an H-UDI interrupt or H-UDI reset, and these exception requests are
accepted in this mode. In standby mode, neither an H-UDI interrupt nor an H-UDI reset is
accepted.
3. In standby mode, the H-UDI function cannot be used. Furthermore, TCK must be retained at a
high level when entering the standby mode in order to retain the TAP state before and after
standby mode.
4. The H-UDI is used for emulator connection. Therefore, H-UDI functions cannot be used when
an emulator is used.
Rev. 3.0, 04/02, page 800 of 1064