R4F24269NVFQV Renesas Electronics America, R4F24269NVFQV Datasheet - Page 334

• Manufacturer Part Number: R4F24269NVFQV
• Description: MCU 256KB FLASH 64K 144-LQFP
• Manufacturer: Renesas Electronics America
• Series: H8® H8S/2400r

Specifications of R4F24269NVFQV

• Core Processor: H8S/2600
• Core Size: 16/32-Bit
• Speed: 33MHz
• Connectivity: EBI/EMI, I²C, IrDA, SCI, SSU, UART/USART
• Peripherals: DMA, POR, PWM, WDT
• Number Of I /o: 96
• Program Memory Size: 256KB (256K x 8)
• Program Memory Type: FLASH
• Ram Size: 64K x 8
• Voltage - Supply (vcc/vdd): 3 V ~ 3.6 V
• Data Converters: A/D 10x10b, D/A 2x8b
• Oscillator Type: External
• Operating Temperature: -20°C ~ 75°C
• Package / Case: 144-LQFP
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Eeprom Size: -

H8S/2426, H8S/2426R, H8S/2424 Group
Section 6 Bus Controller (BSC)
6.11
Write Data Buffer Function
This LSI has a write data buffer function for the external data bus. Using the write data buffer
function enables external writes and DMA single address mode transfers to be executed in parallel
with internal accesses. The write data buffer function is made available by setting the WDBE bit
to 1 in BCR.
Figure 6.95 shows an example of the timing when the write data buffer function is used. When this
function is used, if an external address space write or DMA single address mode transfer continues
for two states or longer, and there is an internal access next, an external write only is executed in
the first state, but from the next state onward an internal access (on-chip memory or internal I/O
register read/write) is executed in parallel with the external address space write rather than waiting
until it ends.
On-chip memory read Internal I/O register read
External write cycle
T
T
T
T
T
1
2
W
W
3
φ
Internal address bus
Internal memory
Internal I/O register address
Internal read signal
External address
A23 to A0
CSn
External space
write
HWR, LWR
D15 to D0
Figure 6.95 Example of Timing when Write Data Buffer Function Is Used
Page 304 of 1372
REJ09B0466-0350 Rev. 3.50
Jul 09, 2010