Direct Memory Access Controller
LH79524/LH79525 User’s Guide
5-8
Version 1.0
5.2.2.3 Maximum Count Register (MAX)
The Maximum Count Register must be programmed with the maximum number of data
units of the next DMA transfer. A data unit equals the source-to-DMA data width (byte, half-
word or word). When the DMA Controller is enabled, the content of the Maximum Count
Register loads into the Terminal Count Register.
If the maximum count is programmed to 1, the DMA Controller performs a single transfer
only and sets the terminal count. If the maximum count is programmed to 0, the DMA Con-
troller does not perform any function.
The maximum terminal count is limited by a 16-bit value. (2
16
– 1).
Table 5-12. MAX Register
BIT
31
30
29
28
27
26
25
24
23
22
21
20
19
18
17
16
FIELD
///
RESET
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
RW
RO
RO
RO
RO
RO
RO
RO
RO
RO
RO
RO
RO
RO
RO
RO
RO
BIT
15
14
13
12
11
10
9
8
7
6
5
4
3
2
1
0
FIELD
MAXCOUNT
RESET
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
RW
RW
RW
RW
RW
RW
RW
RW
RW
RW
RW
RW
RW
RW
RW
RW
RW
ADDR
DATASTREAM x BASE + 0x010
Table 5-13. MAX Fields
BITS
NAME
DESCRIPTION
31:16
///
Reserved
Reading returns 0. Write the reset value.
15:0
MAXCOUNT
Maximum Count
This field contains the maximum data unit count.