HD6417616 RENESAS [Renesas Technology Corp], HD6417616 Datasheet - Page 304

• Manufacturer Part Number: HD6417616
• Description: 32-Bit RISC Microcomputer SuperH™ RISC engine Family/SH7600 Series
• Manufacturer: RENESAS [Renesas Technology Corp]

Section 7 Bus State Controller (BSC)
7.2.9
The 8-bit counter RTCNT counts up with input clocks. The clock select bit of RTCSR selects an
input clock. RTCNT values can always be read/written by the CPU. When RTCNT matches
RTCOR, RTCNT is cleared. Returns to 0 after it counts up to 255.
Bits 15 to 8—Reserved: These bits are always read as 0. The write value should always be 0.
7.2.10
RTCOR is an 8-bit read/write register. The values of RTCOR and RTCNT are constantly
compared. When the values correspond, the compare match flag (CMF) in RTCSR is set and
RTCNT is cleared to 0. When the refresh bit (RFSH) in the individual memory control register
(MCR) is set to 1, a refresh request signal occurs. The refresh request signal is held until refresh
operation is actually performed. If the refresh request is not processed before the next match, the
previous request becomes ineffective.
Rev. 2.00 Mar 09, 2006 page 278 of 906
REJ09B0292-0200
Initial value:
Initial value:
Initial value:
Initial value:
Refresh Timer Counter (RTCNT)
Refresh Time Constant Register (RTCOR)
R/W:
R/W:
R/W:
R/W:
Bit:
Bit:
Bit:
Bit:
R/W
R/W
15
15
—
—
R
R
0
7
0
0
7
0
R/W
R/W
14
14
—
—
R
R
0
6
0
0
6
0
R/W
R/W
13
13
—
—
R
R
0
5
0
0
5
0
R/W
R/W
12
12
—
—
R
R
0
4
0
0
4
0
R/W
R/W
11
11
—
—
R
R
0
3
0
0
3
0
R/W
R/W
10
10
—
—
R
R
0
2
0
0
2
0
R/W
R/W
—
—
R
R
9
0
1
0
9
0
1
0
R/W
R/W
—
—
R
R
8
0
0
0
8
0
0
0