h8s-2172 Renesas Electronics Corporation., h8s-2172 Datasheet - Page 185

• Manufacturer Part Number: h8s-2172
• Description: Renesas 16-bit Single-chip Microcomputer H8s Family H8s-2100 Series
• Manufacturer: Renesas Electronics Corporation.

This LSI has an on-chip DMA controller (DMAC) which can carry out data transfer on up to 4
channels.
7.1
• Number of channels: Four channels
• Address space: Physical address space (16-Mbyte external space)
• Transfer data length: Byte, word, or longword can be selected.
• Maximum number of transfers: 16,777,215/infinite (free-running)
• Address mode: Dual address mode or single address mode can be selected.
• Transfer request: The DMAC transfer activation requests are as follows.
• Bus mode: Cycle steal mode or burst mode can be selected.
• Transfer mode: Normal mode or block transfer mode can be selected.
• Interrupt request: An interrupt request can be sent to the CPU at the end of the specified
EDMA261A_000120020400
Dual address mode
Addresses of transfer source and transfer destination are accessed.
Values set in the internal DMAC register are addresses to be accessed for transfer source and
transfer destination.
Single data transfer requires two bus cycles.
Single address mode
The peripheral device of transfer source or transfer destination is accessed by the DACK signal
and another one is accessed by the address. Single data transfer requires one bus cycle.
External request
Four DREQ pins. Low-level detection or falling-edge detection can be selected.
External requests can be accepted on all channels.
Auto request
A transfer request is automatically generated from the internal DMAC.
On-chip USB
A transfer request can be accepted from the on-chip USB on all channels.
Normal mode
Single data transfer is performed for single transfer request.
The number of transfers is specified as 24 bits (max. 16 Mbytes)
Block transfer mode (only for external request)
Single block (specified number) data transfer is performed for single transfer request.
number of transfers.
Features
Section 7 DMA Controller (DMAC)
Rev. 2.00, 03/04, page 153 of 534