HD6417660 RENESAS [Renesas Technology Corp], HD6417660 Datasheet - Page 285

• Manufacturer Part Number: HD6417660
• Description: Renesas 32-Bit RISC Microcomputer
• Manufacturer: RENESAS [Renesas Technology Corp]

9.4.7
RTCOR is a 32-bit register. When RTCOR matches RTCNT, the CMF bit in RTCSR is set to 1
and RTCNT is cleared to 0.
When the RFSH bit in SDCR is 1, a memory refresh request is issued by this matching signal.
This request is maintained until the refresh operation is performed. If the request is not processed
when the next matching occurs, the previous request is ignored.
When the RTCOR is written, the upper 16 bits of the write data must be H'A55A to cancel write
protection.
9.4.8
RWTCNT is a 7-bit counter. This counter starts to increment by synchronizing the CKIO after a
power-on reset is released, and stops when the value reaches H'007F. External bus access is
suspended while the counter is operating. This counter is provided to minimize the time from
releasing a reset for flash memory to the first access. This register cannot be read or written to.
Bit
31 to 8
7 to 0
Refresh Time Constant Register (RTCOR)
Reset Wait Counter (RWTCNT)
Bit Name


Initial
Value
All 0
All 0
R/W Description
R
R/W Refresh Time
Write Protection
These bits are always read as 0. When writing to these bits,
the upper 16-bit of the write data should be H′A55A to cancel
write protection. The lower 8-bit is should always be 0. If
other value is written to these bits, correct operation cannot
be guaranteed.
Specify the upper limit value of the refresh timer counter
(RTCNT).
Rev. 1.00, 02/04, page 247 of 804