Operation; Overview - Renesas F-ZTAT H8 Series Hardware Manual

Section 7 Refresh Controller
7.3

Operation

7.3.1

Overview

One of three functions can be selected for the H8/3048 Group refresh controller: interfacing to
DRAM connected to area 3, interfacing to pseudo-static RAM connected to area 3, or interval
timing. Table 7.3 summarizes the register settings when these three functions are used.
Table 7.3 Refresh Controller Settings
Register Settings
RFSHCR SRFMD
PSRAME
DRAME
CAS/WE
M9/M8
RFSHE
RCYCE
RTCOR
RTMCSR CKS2 to
CKS0
CMF
CMIE
P8DDR P8 DDR
1
ABWCR ABW3
Rev. 7.00 Sep 21, 2005 page 168 of 878
REJ09B0259-0700
DRAM Interface
Selects self-refresh
mode
Cleared to 0
Set to 1
Selects 2CAS or
2WE mode
Selects column
addressing mode
Selects RFSH signal
output
Selects insertion of
refresh cycles
Refresh interval
setting
Set to 1 when
RTCNT = RTCOR
Cleared to 0
Set to 1 (CS output)
3
Cleared to 0
Usage
PSRAM Interface
Selects self-refresh
mode
Set to 1
Cleared to 0
—
—
Selects RFSH signal
output
Selects insertion of
refresh cycles
Refresh interval
setting
Set to 1 when
RTCNT = RTCOR
Cleared to 0
Set to 1 (CS output)
3
—
Interval Timer
Cleared to 0
Cleared to 0
Cleared to 0
—
—
Cleared to 0
—
Interrupt interval
setting
Set to 1 when
RTCNT = RTCOR
Enables or disables
interrupt requests
Set to 0 or 1
—