HD64F2676VFC33 Renesas Electronics America, HD64F2676VFC33 Datasheet - Page 366

• Manufacturer Part Number: HD64F2676VFC33
• Description: IC H8S MCU FLASH 256K 144-QFP
• Manufacturer: Renesas Electronics America
• Series: H8® H8S/2600r

Specifications of HD64F2676VFC33

• 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 Size: 256KB (256K x 8)
• Program Memory Type: FLASH
• Ram Size: 8K x 8
• Voltage - Supply (vcc/vdd): 3 V ~ 3.6 V
• Data Converters: A/D 12x10b; D/A 4x8b
• Oscillator Type: Internal
• Operating Temperature: -20°C ~ 75°C
• Package / Case: 144-QFP
• Lead Free Status / RoHS Status: Contains lead / RoHS non-compliant
• Eeprom Size: -

Section 7 DMA Controller (DMAC)
DREQ pin sampling is performed every cycle, with the rising edge of the next cycle after the
end of the DMABCR write cycle for setting the transfer enabled state as the starting point.
When the DREQ pin low level is sampled while acceptance by means of the DREQ pin is
possible, the request is held in the DMAC. Then, when activation is initiated in the DMAC, the
request is cleared, and DREQ pin high level sampling for edge detection is started. If DREQ pin
high level sampling has been completed by the time the DMA write cycle ends, acceptance
resumes after the end of the write cycle, DREQ pin low level sampling is performed again, and
this operation is repeated until the transfer ends.
Figure 7.23 shows an example of block transfer mode transfer activated by the DREQ pin falling
edge.
Rev. 3.00 Mar 17, 2006 page 314 of 926
REJ09B0283-0300
[1]
[2] [5] The request is cleared at the next bus break, and activation is started in the DMAC.
[3] [6] Start of DMA cycle; DREQ pin high level sampling on the rising edge of
[4] [7] When the DREQ pin high level has been sampled, acceptance is resumed after the write cycle
Note: In write data buffer mode, bus breaks from [2] to [7] may be hidden, and not visible.
DREQ
Address
bus
DMA
control
Channel
Figure 7.22 Example of DREQ
Acceptance after transfer enabling; the DREQ pin low level is sampled on the rising edge of ,
and the request is held.
is completed.
(As in [1], the DREQ pin low level is sampled on the rising edge of , and the request is held.)
Idle
[1]
Request
Bus release
of 2 cycles
Minimum
[2]
Read
[3]
Transfer source
Request clear period
DREQ
DREQ
DREQ Pin Falling Edge Activated Normal Mode Transfer
DMA
read
Write
Transfer destination
Acceptance resumes
DMA
write
Idle
[4]
Request
of 2 cycles
Minimum
release
Bus
[5]
Read
[6]
Transfer source
Request clear period
DMA
read
Write
starts.
Transfer destination
Acceptance resumes
DMA
write
Idle
[7]
release
Bus