HD64F2676VFC33 Renesas Electronics America, HD64F2676VFC33 Datasheet - Page 270

• Manufacturer Part Number: HD64F2676VFC33
• Description: IC H8S MCU FLASH 256K 144-QFP
• Manufacturer: Renesas Electronics America
• Series: H8® H8S/2600r

Specifications of HD64F2676VFC33

• Core Processor: H8S/2600
• Core Size: 16-Bit
• Speed: 33MHz
• Connectivity: IrDA, SCI
• Peripherals: DMA, POR, PWM, WDT
• Number Of I /o: 103
• Program Memory Size: 256KB (256K x 8)
• Program Memory Type: FLASH
• Ram Size: 8K x 8
• Voltage - Supply (vcc/vdd): 3 V ~ 3.6 V
• Data Converters: A/D 12x10b; D/A 4x8b
• Oscillator Type: Internal
• Operating Temperature: -20°C ~ 75°C
• Package / Case: 144-QFP
• Lead Free Status / RoHS Status: Contains lead / RoHS non-compliant
• Eeprom Size: -

Section 6 Bus Controller (BSC)
Auto Refreshing: To select auto refreshing, set the RFSHE bit to 1 in REFCR.
With auto 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 synchronous DRAM used.
When bits RTCK2 to RTCK0 are set, RTCNT starts counting up. RTCNT and RTCOR settings
should therefore be completed before setting bits RTCK2 to RTCK0. Auto refresh timing is shown
in figure 6.54.
Since the refresh counter operation is the same as the operation in the DRAM interface, see
section 6.6.12, Refresh Control.
When the continuous synchronous DRAM space is set, access to external space other than
continuous synchronous DRAM space cannot be performed in parallel during the auto refresh
period, since the setting of the CBRM bit of REFCR is ignored.
T Rp
T Rr
T Rc1
T Rc2
SDRAM
Address bus
Precharge-sel
RAS
CAS
WE
CKE
High
PALL
REF
NOP
Figure 6.54 Auto Refresh Timing
Rev. 3.00 Mar 17, 2006 page 218 of 926
REJ09B0283-0300