3069RF-ZTAT Datasheet, PDF (155/1003 Pages) Renesas Technology Corp – RENESAS 16-BIT SINGLE-CHIP MICROCOMPUTER

6.2.10 Refresh Timer Counter (RTCNT)
Bit
7
6
5
4
3
2
1
0
Initial value 0
0
0
0
0
0
0
0
Read/Write R/W
R/W
R/W
R/W R/W
R/W
R/W
R/W
RTCNT is an 8-bit readable/writable up-counter.
RTCNT is incremented by an internal clock selected by bits CKS2 to CKS0 in RTMCSR. When
RTCNT matches RTCOR (compare match), the CMF flag in RTMCSR is set to 1 and RTCNT is
cleared to H'00. If the RCYCE bit in DRCRB is set to 1 at this time, a refresh cycle is started.
Also, if the CMIE bit in RTMCSR is set to 1, a compare match interrupt (CMI) is generated.
RTCNT is initialized to H'00 by a reset and in standby mode.
6.2.11 Refresh Time Constant Register (RTCOR)
Bit
7
6
5
4
3
2
1
0
Initial value 1
1
1
1
1
1
1
1
Read/Write R/W
R/W
R/W
R/W R/W
R/W
R/W
R/W
RTCOR is an 8-bit readable/writable register that determines the interval at which RTCNT is
cleared.
RTCOR and RTCNT are constantly compared. When their values match, the CMF flag is set to 1
in RTMCSR, and RTCNT is simultaneously cleared to H'00.
RTCOR is initialized to H'FF by a reset and in hardware standby mode. It is not initialized in
software standby mode.
Note: Only byte access can be used on this register.
Rev. 5.0, 09/04, page 133 of 978