HD6413007F20 Renesas Electronics America, HD6413007F20 Datasheet - Page 189

• Manufacturer Part Number: HD6413007F20
• Description: IC H8 MCU ROMLESS 5V 100QFP
• Manufacturer: Renesas Electronics America
• Series: H8® H8/300Hr

Specifications of HD6413007F20

• Core Processor: H8/300H
• Core Size: 16-Bit
• Speed: 20MHz
• Connectivity: SCI, SmartCard
• Peripherals: DMA, PWM, WDT
• Number Of I /o: 35
• Program Memory Type: ROMless
• Ram Size: 4K x 8
• Voltage - Supply (vcc/vdd): 2.7 V ~ 5.5 V
• Data Converters: A/D 8x10b; D/A 2x8b
• Oscillator Type: Internal
• Operating Temperature: -20°C ~ 75°C
• Package / Case: 100-QFP
• Lead Free Status / RoHS Status: Contains lead / RoHS non-compliant
• Eeprom Size: -
• Program Memory Size: -

6. Bus Controller
When RAS down mode is selected, the CAS-before-RAS refresh function provided with this
DRAM interface must always be used as the DRAM refreshing method. When a refresh
operation is performed, the RAS signal goes high immediately beforehand. The refresh
interval setting must be made so that the maximum DRAM RAS pulse width specification is
observed.
When the self-refresh function is used, the RDM bit must be cleared to 0, and RAS up mode
selected, before executing a SLEEP instruction in order to enter software standby mode.
Select RAS down mode again after exiting software standby mode.
Note that RAS down mode cannot be used when HWR and LWR are selected for UCAS and
LCAS, a device other than DRAM is connected to external space, and HWR and LWR are
used as write strobes.
• RAS Up Mode
To select RAS up mode, clear the RDM bit to 0 in DRCRA. Each time access to DRAM space
is interrupted and another space is accessed, the RAS signal returns to the high level. Burst
operation is only performed if DRAM space is continuous. Figure 6.23 shows an example of
the timing in RAS up mode.
External space
DRAM access
DRAM access
access
T
Tr
T
T
T
T
T
T
p
c1
c2
c1
c2
1
2
φ
A
to A
23
0
AS
CSn(RAS)
PB4/PB5
(UCAS/LCAS)
D
to D
15
0
Note: n = 2 to 5
Figure 6.23 Example of Operation Timing in RAS Up Mode
Rev.5.00 Sep. 12, 2007 Page 159 of 764
REJ09B0396-0500