DF2328BVF25V Renesas Electronics America, DF2328BVF25V Datasheet - Page 241

• Manufacturer Part Number: DF2328BVF25V
• Description: IC H8S MCU FLASH 256K 128QFP
• Manufacturer: Renesas Electronics America
• Series: H8® H8S/2300r

Specifications of DF2328BVF25V

• Core Processor: H8S/2000
• Core Size: 16-Bit
• Speed: 25MHz
• 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): 2.7 V ~ 3.6 V
• Data Converters: A/D 8x10b; D/A 2x8b
• Oscillator Type: Internal
• Operating Temperature: -20°C ~ 75°C
• Package / Case: 128-QFP
• For Use With: EDK2329 - DEV EVALUATION KIT H8S/2329
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Eeprom Size: -
• Other names: HD64F2328BVF25V

6.9
The chip 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.
Note: * The DMAC is not supported in the H8S/2321.
Note: n = 0 to 7
External
space
write
Internal address bus
Internal read signal
Figure 6.36 Example of Timing when Write Data Buffer Function is Used
Write Data Buffer Function
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
Rev.6.00 Sep. 27, 2007 Page 209 of 1268
T
W
Internal I/O register address
T
W
Section 6 Bus Controller
REJ09B0220-0600
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3