
13. DMACII
13. DMACII
DMACII perform memory-to-memory transfer, immediate data transfer, and calculation transfer which transfers a
result of the addition of two data. A DMACII transfer occurs in response to interrupt requests from the peripheral
functions.
Table 13.1
DMACII Specifications
NOTES:
1. When a 16-bit data is transferred to a destination address 0FFFFh, it is transferred to addresses 0FFFFh and
10000h. Likewise, when a source address is 0FFFFh, a 16-bit data in addresses 0FFFFh and 10000h is
transferred to a given destination address.
2.
The actual transferable space varies depending on internal RAM capacity.
13.1
DMACII Settings
Set up the following registers and tables to activate DMACII.
RLVL register
DMACII Index
Interrupt control register of the peripheral function causing a DMACII request
The relocatable vector table of the peripheral function causing a DMACII request
IRLT bit in the IIOiIE register (i = 0 to 11) if using the intelligent I/O, CAN, INTj (j = 6 to 8), UARTk (k = 5,
6) transmit, or UARTk receive interrupt. Refer to 10. Interrupts for details on the IIOiIE register.
13.1.1
RLVL Register
When the DMACII bit is set to 1 (interrupt priority level 7 is used for DMACII transfer) and the FSIT bit to 0
(interrupt priority level 7 is used for normal interrupt), DMACII is activated by an interrupt request from any
peripheral functions with bits ILVL2 to ILVL0 in the interrupt control register set to 111b (level 7).
Item
Specification
DMACII request source
Interrupt requests generated by any peripheral functions with bits ILVL2 to ILVL0
in the interrupt control register set to 111b (level 7)
Transfer data
- Data in a memory location is transferred to another memory location
(memory-to-memory transfer)
- Immediate data is transferred to a memory location (immediate data transfer)
- Data in a memory location (or immediate data) + data in another memory location
are transferred to the other memory location (calculation transfer)
Transfer unit
8 bits or 16 bits
Transfer space
64-Kbyte space in addresses 00000h to 0FFFFh
(1)(2)Transfer address
Fixed address: one specified address
Incremented address: address which is incremented by the transfer unit on each
successive access.
(Selectable for source address and destination address individually)
Transfer mode
Single transfer, burst transfer
Chain transfer function
Address indicated by a interrupt vector for DMACII index is switched when a
transfer counter reaches zero
End-of-transfer interrupt
Interrupt occurs when a transfer counter reaches zero
Multiple transfer function
Multiple data can be transferred by one DMACII transfer request