DF2170BVTE33V Renesas Electronics America, DF2170BVTE33V Datasheet - Page 171

• Manufacturer Part Number: DF2170BVTE33V
• Description: IC H8S/2170 MCU FLASH 100-TQFP
• Manufacturer: Renesas Electronics America
• Series: H8® H8S/2100r

Specifications of DF2170BVTE33V

• Core Processor: H8S/2000
• Core Size: 16-Bit
• Speed: 33MHz
• Connectivity: SCI, USB
• Peripherals: DMA, POR, PWM, WDT
• Number Of I /o: 76
• Program Memory Size: 256KB (256K x 8)
• Program Memory Type: FLASH
• Ram Size: 32K x 8
• Voltage - Supply (vcc/vdd): 3 V ~ 3.6 V
• Oscillator Type: External
• Operating Temperature: -20°C ~ 75°C
• Package / Case: 100-TQFP, 100-VQFP
• For Use With: HS0005KCU11H - EMULATOR E10A-USB H8S(X),SH2(A)3DK2166 - DEV EVAL KIT H8S/2166
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Eeprom Size: -
• Data Converters: -

6.6.12
This LSI is provided with a DRAM refresh control function. CAS-before-RAS (CBR) refreshing
is used. In addition, self-refreshing can be executed when the chip enters the software standby
state.
Refresh control is enabled when area 2 is designated as DRAM space in accordance with the
setting of bit DSET in DRAMCR.
CAS-before-RAS (CBR) Refreshing: To select CBR refreshing, set the RFSHE bit to 1 in
REFCR.
With CBR refreshing, RTCNT counts up using the input clock selected by bits RTCK2 to RTCK0
in REFCR, and when the count matches the value set in RTCOR (compare match), refresh control
is performed. At the same time, RTCNT is reset and starts counting up again from H'00.
Refreshing is thus repeated at fixed intervals determined by RTCOR and bits RTCK2 to RTCK0.
Set a value in RTCOR and bits RTCK2 to RTCK0 that will meet the refreshing interval
specification for the DRAM used.
When bits RTCK2 to RTCK0 in REFCR are set, RTCNT starts counting up. RTCNT and RTCOR
settings should therefore be completed before setting bits RTCK2 to RTCK0. RTCNT operation is
shown in figure 6.36, compare match timing in figure 6.37, and CBR refresh timing in figure 6.38.
Access to external space other than DRAM space is not possible in parallel during the CBR
refresh period.
RTCOR
H'00
Refresh request
Refresh Control
RTCNT
Figure 6.36 RTCNT Operation
Rev. 2.00, 03/04, page 137 of 534