
8.1.3 Functional Overview
Table 8-1 gives an overview of the DMAC functions.
Table 8-1 DMAC Functional Overview
Address
Reg. Length
Destina-
Transfer Mode
Short
address
mode
Activation
Compare match/input 24
capture A interrupts
from ITU channels
0 to 3
Transmit-data-empty
interrupt from SCI
channel 0
Receive-data-full
interrupt from SCI
channel 0
External request
Source tion
8
8
24
24
8
Auto-request
External request
24
24
Compare match/
input capture A
interrupts from ITU
channels 0 to 3
External request
24
24
I/O mode
Transfers one byte or one word
per request
Increments or decrements the
memory address by 1 or 2
Executes 1 to 65,536 transfers
Idle mode
Transfers one byte or one word
per request
Holds the memory address fixed
Executes 1 to 65,536 transfers
Repeat mode
Transfers one byte or one word
per request
Increments or decrements the
memory address by 1 or 2
Executes a specified number (1 to
255) of transfers, then returns to
the initial state and continues
Normal mode
Auto-request
—Retains the transfer request
internally
—Executes a specified number
(1 to 65,536) of transfers
continuously
—Selection of burst mode or
cycle-steal mode
External request
—Transfers one byte or one word
per request
—Executes 1 to 65,536 transfers
Block transfer
Transfers one block of a specified
size per request
Executes 1 to 65,536 transfers
Allows either the source or
destination to be a fixed block
area
Block size can be 1 to 255 bytes
or words
Full
address
mode
187