D12674RVFQ33D Renesas Electronics America, D12674RVFQ33D Datasheet - Page 268

• Manufacturer Part Number: D12674RVFQ33D
• Description: MCU 3V 0K I-TEMP 144-QFP
• Manufacturer: Renesas Electronics America
• Series: H8® H8S/2600r

Specifications of D12674RVFQ33D

• 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 Type: ROMless
• Ram Size: 32K x 8
• Voltage - Supply (vcc/vdd): 3 V ~ 3.6 V
• Data Converters: A/D 12x10b; D/A 4x8b
• Oscillator Type: Internal
• Operating Temperature: -40°C ~ 85°C
• Package / Case: 144-LQFP
• Lead Free Status / RoHS Status: Contains lead / RoHS non-compliant
• Eeprom Size: -
• Program Memory Size: -
• Other names: HD6412674RVFQ33D; HD6412674RVFQ33D

Section 6 Bus Controller (BSC)
RAS Down Mode: Even when burst operation is selected, it may happen that access to continuous
synchronous DRAM space is not continuous, but is interrupted by access to another space. In this
case, if the row address active state is held during the access to the other space, the read or write
command can be issued without ACTV command generation similarly to DRAM RAS down
mode.
To select RAS down mode, set the BE bit to 1 in DRAMCR regardless of the RCDM bit settings.
The operation corresponding to DRAM RAS up mode is not supported by this LSI.
Figure 6.53 shows an example of the timing in RAS down mode.
Note, however, the next continuous synchronous DRAM space access is a full access if:
There is synchronous DRAM in which time of the active state of each bank is restricted. If it is not
guaranteed that other row address are accessed in a period in which program execution ensures the
value (software standby, sleep, etc.), auto refresh or self refresh must be set, and the restrictions of
the maximum active state time of each bank must be satisfied. When refresh is not used, programs
must be developed so that the bank is not in the active state for more than the specified time.
Rev. 3.00 Mar 17, 2006 page 216 of 926
REJ09B0283-0300
a refresh operation is initiated in the RAS down state
self-refreshing is performed
the chip enters software standby mode
the external bus is released
the BE bit is cleared to 0
the mode register of the synchronous DRAM is set