HD6417320 RENESAS [Renesas Technology Corp], HD6417320 Datasheet - Page 391

• Manufacturer Part Number: HD6417320
• Description: Renesas 32-Bit RISC Microcomputer SuperHTM RISC engine Family / SH7700 Series
• Manufacturer: RENESAS [Renesas Technology Corp]

9.4.6
RTCNT is an 8-bit counter that increments using the clock selected by bits CKS2 to CKS0 in
RTCSR. When RTCNT matches RTCOR, RTCNT is cleared to 0. The value in RTCNT returns to
0 after counting up to 255. When the RTCNT is written, the upper 16 bits of the write data must
be H'A55A to cancel write protection.
Bit
2
1
0
Bit
31 to 8
7 to 0
Refresh Timer Counter (RTCNT)
Bit Name
RRC2
RRC1
RRC0
Bit Name


Initial
Value
0
0
0
Initial
Value
All 0
All 0
R/W
R/W
R/W
R/W
R/W
R
R/W
Description
Reserved
These bits are always read as 0. The write value should
always be 0.
8-bit Counter
Description
Refresh Count
Specify the number of continuous refresh cycles, when the
refresh request occurs after the coincidence of the values of
the refresh timer counter (RTCNT) and the refresh time
constant register (RTCOR). These bits can make the period
of occurrence of refresh long.
000: Once
001: Twice
010: 4 times
011: 6 times
100: 8 times
101: Reserved (setting prohibited)
110: Reserved (setting prohibited)
111: Reserved (setting prohibited)
Rev. 3.00 Jan. 18, 2008 Page 329 of 1458
Section 9
Bus State Controller (BSC)
REJ09B0033-0300