DF61657CN35FTV Renesas Electronics America, DF61657CN35FTV Datasheet - Page 327

• Manufacturer Part Number: DF61657CN35FTV
• Description: IC H8SX/1657 MCU FLASH 120TQFP
• Manufacturer: Renesas Electronics America
• Series: H8® H8SX/1600r

Specifications of DF61657CN35FTV

• Core Processor: H8SX
• Core Size: 32-Bit
• Speed: 35MHz
• Connectivity: SCI, SmartCard
• Peripherals: DMA, PWM, WDT
• Number Of I /o: 82
• Program Memory Size: 768KB (768K x 8)
• Program Memory Type: FLASH
• Ram Size: 24K x 8
• Voltage - Supply (vcc/vdd): 3 V ~ 3.6 V
• Data Converters: A/D 8x10b; D/A 2x8b
• Oscillator Type: Internal
• Operating Temperature: -20°C ~ 75°C
• Package / Case: 120-TQFP, 120-VQFP
• For Use With: 3DK1657 - DEV EVAL KIT FOR H8SX/1657
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Eeprom Size: -

Section 7 DMA Controller (DMAC)
7.7.2
Bus Arbitration among DMAC and Other Bus Masters
When DMA transfer cycles are consecutively performed, bus cycles of other bus masters may be
inserted between the transfer cycles. The DMAC can release the bus temporarily to pass the bus to
other bus masters.
The consecutive DMA transfer cycles may not be divided according to the transfer mode settings
to achieve high-speed access.
The read and write cycles of a DMA transfer are not separated. Refreshing, external bus release,
and on-chip bus master (CPU or DTC) cycles are not inserted between the read and write cycles of
a DMA transfer.
In block transfer mode and an auto request transfer by burst access, bus cycles of the DMA
transfer are consecutively performed. For this duration, since the DMAC has priority over the
CPU and DTC, accesses to the external space is suspended (the IBCCS bit in the bus control
register 2 (BCR2) is cleared to 0).
When the bus is passed to another channel or an auto request transfer by cycle stealing, bus cycles
of the DMAC and on-chip bus master are performed alternatively.
When the arbitration function among the DMAC and on-chip bus masters is enabled by setting the
IBCCS bit in BCR2, the bus is used alternatively except the bus cycles which are not separated.
For details, see section 6, Bus Controller (BSC).
A conflict may occur between external space access of the DMAC and an external bus release
cycle. Even if a burst or block transfer is performed by the DMAC, the transfer is stopped
temporarily and a cycle of external bus release is inserted by the BSC according to the external
bus priority (when the CPU external access and the DTC external access do not have priority over
a DMAC transfer, the transfers are not operated until the DMAC releases the bus).
In dual address mode, the DMAC releases the external bus after the external space write cycle.
Since the read and write cycles are not separated, the bus is not released.
An internal space (on-chip memory and internal I/O registers) access of the DMAC and an
external bus release cycle may be performed at the same time.
Rev. 2.00 Jun. 28, 2007 Page 301 of 864
REJ09B0341-0200