HD64F2676VFC33 Renesas Electronics America, HD64F2676VFC33 Datasheet - Page 272

• 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)
When the interval specification from the REF command to the ACTV cannot be satisfied, setting
the RLW1 and RLW0 bits of REFCR enables one to three wait states to be inserted in the refresh
cycle. Set the optimum number of waits according to the synchronous DRAM connected and the
operating frequency of this LSI. Figure 6.56 shows the timing when one wait state is inserted.
T
T
T
T
T
Rp
Rr
Rr1
Rcw
Rc2
SDRAM
Address bus
Precharge-sel
RAS
CAS
WE
CKE
High
NOP
PALL
REF
Figure 6.56 Auto Refresh Timing
(TPC = 0, TPC0 = 0, RLW1 = 0, RLW0 = 1)
Self-Refreshing: A self-refresh mode (battery backup mode) is provided for synchronous DRAM
as a kind of standby mode. In this mode, refresh timing and refresh addresses are generated within
the synchronous DRAM.
To select self-refreshing, set the RFSHE bit to 1 in REFCR. When a SLEEP instruction is
executed to enter software standby mode, the SELF command is issued, as shown in figure 6.57.
When software standby mode is exited, the SLFRF bit in REFCR is cleared to 0 and self-refresh
mode is exited automatically. If an auto refresh request occurs when making a transition to
software standby mode, auto refreshing is executed, then self-refresh mode is entered.
Rev. 3.00 Mar 17, 2006 page 220 of 926
REJ09B0283-0300