D12321VF20V Renesas Electronics America, D12321VF20V Datasheet - Page 194

• Manufacturer Part Number: D12321VF20V
• Description: IC H8S/2321 MCU ROMLESS 128QFP
• Manufacturer: Renesas Electronics America
• Series: H8® H8S/2300r

Specifications of D12321VF20V

• Core Processor: H8S/2000
• Core Size: 16-Bit
• Speed: 20MHz
• Connectivity: SCI, SmartCard
• Peripherals: POR, PWM, WDT
• Number Of I /o: 86
• Program Memory Type: ROMless
• Ram Size: 4K x 8
• Voltage - Supply (vcc/vdd): 2.7 V ~ 3.6 V
• Data Converters: A/D 8x10b; D/A 2x8b
• Oscillator Type: Internal
• Operating Temperature: -20°C ~ 75°C
• Package / Case: 128-QFP
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Eeprom Size: -
• Program Memory Size: -

Section 6 Bus Controller
6.2.7
DRAMCR is an 8-bit readable/writable register that selects the DRAM refresh mode and refresh
counter clock, and controls the refresh timer.
DRAMCR is initialized to H'00 by a reset and in hardware standby mode. It is not initialized in
software standby mode.
Note: In the H8S/2321 this register is reserved and must not be accessed.
Bit 7—Refresh Control (RFSHE): Selects whether or not refresh control is performed. When
refresh control is not performed, the refresh timer can be used as an interval timer.
Bit 7
RFSHE
0
1
Bit 6—RAS-CAS Wait (RCW): Controls wait state insertion in DRAM interface CAS-before-
RAS refreshing.
Bit 6
RCW
0
1
Bit 5—Refresh Mode (RMODE): When refresh control is performed (RFSHE = 1), selects
whether or not self-refresh control is performed in software standby mode.
Bit 5
RMODE
0
1
Rev.6.00 Sep. 27, 2007 Page 162 of 1268
REJ09B0220-0600
Bit
Initial value :
R/W
DRAM Control Register (DRAMCR)
Description
Refresh control is not performed
Refresh control is performed
Description
Wait state insertion in CAS-before-RAS refreshing disabled
RAS falls in T
One wait state inserted in CAS-before-RAS refreshing
RAS falls in T
Description
Self-refreshing is not performed in software standby mode
Self-refreshing is performed in software standby mode
:
:
RFSHE
R/W
7
0
Rr
Rc1
cycle
RCW
cycle
R/W
6
0
RMODE
R/W
5
0
CMF
R/W
4
0
CMIE
R/W
3
0
CKS2
R/W
2
0
CKS1
R/W
1
0
(Initial value)
(Initial value)
(Initial value)
CKS0
R/W
0
0