13 DMA CONTROLLER (DMAC)
S1C33L26 TECHNICAL MANUAL
Seiko Epson Corporation
13-1
DMA Controller (DMAC)
13
DMAC Module Overview
13.1
The S1C33L26 incorporates a DMA controller (DMAC) capable of controlling eight table DMA channels.
The table DMA transfers data according to the control information programmed in the RAM.
The following shows the features of the DMAC.
• Number of channels
Maximum eight channels
• Control information
Programmable in the DSTRAM, IVRAM (Area 3) or an external RAM
(16-byte control infor 16-byte backup data per channel)
• Dual-address transfer
IVRAM (Area 3), an external memory or an internal peripheral module area (from
address 0x300000) can be specified as the transfer source and destination.
1. Data transfer within IVRAM
2. Data transfer between IVRAM and an external memory
3. Data transfer between IVRAM and an internal peripheral module area
4. Data transfer between an external memory and an external memory
5. Data transfer between an external memory and an internal peripheral module area
6. Data transfer within internal peripheral module area
*
Note that Area 0 (including IVRAM relocated to Area 0) cannot be specified as the
transfer source and destination.
• Transfer data size
8 bits, 16 bits or 32 bits
• Transfer mode
1. Single transfer (one unit of data is transferred by one trigger)
2. Successive transfer (specified number of data are transferred by one trigger, with
12-bit transfer counter)
• Transfer address control The source and/or destination addresses can be fixed or incremented in units of the
transfer data size upon completion of transfer.
• Trigger
1. Software trigger via register control
2. Hardware trigger by interrupt source modules
(USI, FSIO, I2S, T16P, T16A5, ADC10, USB)
• Pointer transfer
Transfer data can be specified using the specified source as a pointer.
Transfer data = *(Pointer base a *(Source address))
• Interrupt
End-of-transfer interrupt
• Others
- Auto-reload function for the identical DMA transfers without resetting
- A DMA pause (temporary standby) function of low-priority channel DMA by high-
priority trigger
DMAC Operating Clock
13.2
The DMAC operates with BCLK supplied from the CMU. BCLK does not stop in normal mode and in HALT mode
by default. It can be stopped in HALT mode using a CMU control register. For more information on BCLK, see the
“Clock Management Unit (CMU)” chapter. In SLEEP mode, the CMU stops supplying BCLK to the DMAC.