D12320VF25IV Datasheet, PDF (195/1304 Pages) Renesas Technology Corp – Old Company Name in Catalogs and Other Documents

Section 6 Bus Controller
Bit 4—Compare Match Flag (CMF): Status flag that indicates a match between the values of
RTCNT and RTCOR.
When refresh control is performed (RFSHE = 1), 1 should be written to the CMF bit when writing
to DRAMCR.
Bit 4
CMF
0
1
Description
[Clearing condition]
Cleared by reading the CMF flag when CMF = 1, then writing 0 to the CMF flag
(Initial value)
[Setting condition]
Set when RTCNT = RTCOR
Bit 3—Compare Match Interrupt Enable (CMIE): Enables or disables interrupt requests (CMI)
by the CMF flag when the CMF flag in DRAMCR is set to 1.
When refresh control is performed (RFSHE = 1), the CMIE bit is always cleared to 0.
Bit 3
CMIE
0
1
Description
Interrupt request (CMI) by CMF flag disabled
Interrupt request (CMI) by CMF flag enabled
(Initial value)
Bits 2 to 0—Refresh Counter Clock Select (CKS2 to CKS0): These bits select the clock to be
input to RTCNT from among 7 internal clocks obtained by dividing the system clock (φ). When
the input clock is selected with bits CKS2 to CKS0, RTCNT begins counting up.
Bit 2
CKS2
0
1
Bit 1
CKS1
0
1
0
1
Bit 0
CKS0
0
1
0
1
0
1
0
1
Description
Count operation disabled
Count uses φ/2
Count uses φ/8
Count uses φ/32
Count uses φ/128
Count uses φ/512
Count uses φ/2048
Count uses φ/4096
(Initial value)
Rev.6.00 Sep. 27, 2007 Page 163 of 1268
REJ09B0220-0600