DF2398TE20 Renesas Electronics America, DF2398TE20 Datasheet - Page 188

• Manufacturer Part Number: DF2398TE20
• Description: IC H8S MCU FLASH 256K 120TQFP
• Manufacturer: Renesas Electronics America
• Series: H8® H8S/2300r

Specifications of DF2398TE20

• Core Processor: H8S/2000
• Core Size: 16-Bit
• Speed: 20MHz
• Connectivity: SCI, SmartCard
• Peripherals: DMA, POR, PWM, WDT
• Number Of I /o: 87
• Program Memory Size: 256KB (256K x 8)
• Program Memory Type: FLASH
• Ram Size: 8K x 8
• Voltage - Supply (vcc/vdd): 4.5 V ~ 5.5 V
• Data Converters: A/D 8x10b; D/A 2x8b
• Oscillator Type: Internal
• Operating Temperature: -20°C ~ 75°C
• Package / Case: 120-TQFP, 120-VQFP
• Lead Free Status / RoHS Status: Contains lead / RoHS non-compliant
• Eeprom Size: -
• Other names: HD64F2398TE20; HD64F2398TE20

6.9
The H8S/2357 Group has a write data buffer function in 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 in BCRL to 1.
Figure 6-36 shows an example of the timing when the write data buffer function is used. When this function is used, if an
external write or DMA single address mode transfer continues for 2 states or longer, and there is an internal access next,
only an external write 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 write rather than waiting until it ends.
Rev.6.00 Oct.28.2004 page 158 of 1016
REJ09B0138-0600H
Write Data Buffer Function
External
space
write
Note : n = 0 to 7
Internal address bus
Internal read signal
Figure 6-36 Example of Timing when Write Data Buffer Function is Used
HWR, LWR
D
A
15
23
to D
to A
CSn
0
0
T
1
On-chip memory read Internal I/O register read
T
Internal memory
2
External write cycle
External address
T
W
Internal I/O register address
T
W
T
3