R4F24278NVFQU Renesas Electronics America, R4F24278NVFQU Datasheet - Page 342

• Manufacturer Part Number: R4F24278NVFQU
• Description: MCU 512K/48K 2.7-5.5V 144-LQFP
• Manufacturer: Renesas Electronics America
• Series: H8® H8S/2400r

Specifications of R4F24278NVFQU

• Core Processor: H8S/2600
• Core Size: 16/32-Bit
• Speed: 33MHz
• Connectivity: EBI/EMI, I²C, IrDA, SCI, Smart Card, SPI, SSU, UART/USART
• Peripherals: DMA, POR, PWM, WDT
• Number Of I /o: 98
• Program Memory Size: 512KB (512K x 8)
• Program Memory Type: FLASH
• Eeprom Size: -
• Ram Size: 64K x 8
• Voltage - Supply (vcc/vdd): 3 V ~ 3.6 V
• Data Converters: A/D 16x10b; 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

Section 7 Bus Controller (BSC)
7.11
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 7.95 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 three states or longer and there is an internal access next, an external write only is executed in
the first two states, 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.
Page 312 of 1448
External space
write
Figure 7.95 Example of Timing when Write Data Buffer Function Is Used
Write Data Buffer Function
Internal address bus
Internal read signal
HWR, LWR
D15 to D0
A23 to A0
CSn
φ
T
1
T
On-chip memory read
2
External write cycle
On-chip
memory
T
W
External address
On-chip
memory
H8S/2427, H8S/2427R, H8S/2425 Group
T
W
Internal I/O register read
T
REJ09B0565-0100 Rev. 1.00
register address
W
Internal I/O
T
3
Jul 22, 2010