Z8F6421PM020SC Datasheet, PDF (184/299 Pages) Zilog, Inc. – High Performance 8-Bit Microcontrollers Z8 Encore-R 64K Series

Z8 Encore!^® 64K Series
Product Specification
164
Table 76. DMAx Control Register (DMAxCTL)
BITS
7
6
5
4
3
2
1
0
FIELD ^DEN
DLE
DDIR IRQEN WSEL
RSS
RESET
0
R/W
R/W
ADDR
FB0H, FB8H
DEN—DMAx Enable
0 = DMAx is disabled and data transfer requests are disregarded.
1 = DMAx is enabled and initiates a data transfer upon receipt of a request from the trigger
source.
DLE—DMAx Loop Enable
0 = DMAx reloads the original Start Address and is then disabled after the End Address
data is transferred.
1 = DMAx, after the End Address data is transferred, reloads the original Start Address
and continues operating.
DDIR—DMAx Data Transfer Direction
0 = Register File → on-chip peripheral control register.
1 = on-chip peripheral control register → Register File.
IRQEN—DMAx Interrupt Enable
0 = DMAx does not generate any interrupts.
1 = DMAx generates an interrupt when the End Address data is transferred.
WSEL—Word Select
0 = DMAx transfers a single byte per request.
1 = DMAx transfers a two-byte word per request. The address for the on-chip peripheral
control register must be an even address.
RSS—Request Trigger Source Select
The Request Trigger Source Select field determines the peripheral that can initiate a DMA
transfer. The corresponding interrupts do not need to be enabled within the Interrupt Con-
troller to initiate a DMA transfer. However, if the Request Trigger Source can enable or
disable the interrupt request sent to the Interrupt Controller, the interrupt request must be
enabled within the Request Trigger Source block.
000 = Timer 0.
001 = Timer 1.
010 = Timer 2.
011 = Timer 3.
100 = DMA0 Control register: UART0 Received Data register contains valid data. DMA1
Control register: UART0 Transmit Data register empty.
PS019915-1005
Direct Memory Access Controller