HD64F2149 Datasheet, PDF (755/1035 Pages) Renesas Technology Corp – Hitachi 16-Bit Single-Chip Microcomputer

MSTPCRH and MSTPCRL Bits 7 to 0—Module Stop (MSTP 15 to MSTP 0): These bits
specify module stop mode. See table 24.4 for the method of selecting on-chip supporting modules.
MSTPCRH, MSTPCRL
Bits 7 to 0
MSTP15 to MSTP0 Description
0
Module stop mode is cleared
1
Module stop mode is set
(Initial value of MSTP15, MSTP14)
(Initial value of MSTP13 to MSTP0)
24.3 Medium-Speed Mode
When the SCK2 to SCK0 bits in SBYCR are set to 1 in high-speed mode, the operating mode
changes to medium-speed mode at the end of the bus cycle. In medium-speed mode, the CPU
operates on the operating clock (ø/2, ø/4, ø/8, ø/16, or ø/32) specified by the SCK2 to SCK0 bits.
The bus master other than the CPU (the DTC) also operates in medium-speed mode. On-chip
supporting modules other than the bus masters always operate on the high-speed clock (ø).
In medium-speed mode, a bus access is executed in the specified number of states with respect to
the bus master operating clock. For example, if ø/4 is selected as the operating clock, on-chip
memory is accessed in 4 states, and internal I/O registers in 8 states.
Medium-speed mode is cleared by clearing all of bits SCK2 to SCK0 to 0. A transition is made to
high-speed mode and medium-speed mode is cleared at the end of the current bus cycle.
If a SLEEP instruction is executed when the SSBY bit in SBYCR and the LSON bit in LPWRCR
are cleared to 0, a transition is made to sleep mode. When sleep mode is cleared by an interrupt,
medium-speed mode is restored.
If a SLEEP instruction is executed when the SSBY bit in SBYCR is set to 1, and the LSON bit in
LPWRCR and the PSS bit in TCSR (WDT1) are both cleared to 0, a transition is made to software
standby mode. When software standby mode is cleared by an external interrupt, medium-speed
mode is restored.
When the RES pin is driven low, a transition is made to the reset state, and medium-speed mode is
cleared. The same applies in the case of a reset caused by overflow of the watchdog timer.
When the STBY pin is driven low, a transition is made to hardware standby mode.
Figure 24.2 shows the timing for transition to and clearance of medium-speed mode.
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