D6417729RHF200BV Renesas Electronics America, D6417729RHF200BV Datasheet - Page 455

• Manufacturer Part Number: D6417729RHF200BV
• Description: IC SUPER H MPU ROMLESS 208QFP
• Manufacturer: Renesas Electronics America
• Series: SuperH® SH7700r

Specifications of D6417729RHF200BV

• Core Processor: SH-3 DSP
• Core Size: 32-Bit
• Speed: 200MHz
• Connectivity: EBI/EMI, FIFO, IrDA, SCI, SmartCard
• Peripherals: DMA, POR, WDT
• Number Of I /o: 96
• Program Memory Type: ROMless
• Ram Size: 32K x 8
• Voltage - Supply (vcc/vdd): 1.85 V ~ 2.15 V
• Data Converters: A/D 8x10b; D/A 2x8b
• Oscillator Type: Internal
• Operating Temperature: -20°C ~ 75°C
• Package / Case: 208-QFP Exposed Pad, 208-eQFP, 208-HQFP
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Eeprom Size: -
• Program Memory Size: -

12.3.5
Number of Bus Cycle States: When the DMAC is the bus master, the number of bus cycle states
is controlled by the bus state controller (BSC) in the same way as when the CPU is the bus master.
For details, see section 11, Bus State Controller (BSC).
D D D D R R R R E E E E Q Q Q Q Pin Sampling Timing: In external request mode, the DREQ pin is sampled by clock pulse
(CKIO) falling edge or low level detection. When DREQ input is detected, a DMAC bus cycle is
generated and DMA transfer performed, at the earliest, three states later.
The second and subsequent DREQ sampling operations are started two cycles after the first
sample.
Operation
Cycle-Steal Mode
In cycle-steal mode, the DREQ sampling timing is the same regardless of whether level or
edge detection is used.
For example, in figure 12.17 (cycle-steal mode, level input), DMAC transfer begins, at the
earliest, three cycles after the first sampling is performed. The second sampling is started two
cycles after the first. If DREQ is not detected at this time, sampling is performed in each
subsequent cycle.
Thus, DREQ sampling is performed one step in advance. The third sampling operation is not
performed until the idle cycle following the end of the first DMA transfer.
The above conditions are the same whatever the number of CPU transfer cycles, as shown in
figure 12.18. The above conditions are also the same whatever the number of DMA transfer
cycles, as shown in figure 12.19.
DACK is output in a read in the example in figure 12.17, and in a write in the example in
figure 12.18. In both cases, DACK is output for the same duration as CSn.
Figure 12.20 shows an example in which sampling is executed in all subsequent cycles when
DREQ cannot be detected.
Figure 12.21 shows examples of edge detection in the cycle-steal mode.
Number of Bus Cycle States and D D D D R R R R E E E E Q Q Q Q Pin Sampling Timing
Rev. 5.0, 09/03, page 407 of 806