SH7058 Datasheet, PDF (210/1130 Pages) Renesas Technology Corp – Renesas SuperHTM RISC engine

10.2.3 DMA Transfer Count Registers 0–3 (DMATCR0–DMATCR3)
Bit: 31
30
29
28
27
26
25
24
—
—
—
—
—
—
—
—
Initial value: 0
0
0
0
0
0
0
0
R/W: R
R
R
R
R
R
R
R
Bit: 23
22
21
20
19
18
17
16
Initial value: —
—
—
—
—
—
—
—
R/W: R/W R/W R/W R/W R/W R/W R/W R/W
Bit: 15
14
13
12
11
10
9
8
Initial value: —
—
—
—
—
—
—
—
R/W: R/W R/W R/W R/W R/W R/W R/W R/W
Bit: 7
6
5
4
3
2
1
0
Initial value: —
—
—
—
—
—
—
—
R/W: R/W R/W R/W R/W R/W R/W R/W R/W
DMA transfer count registers 0–3 (DMATCR0–DMATCR3) are 24-bit read/write registers that
specify the transfer count for the channel (byte count, word count, or longword count) in bits 23 to
0. Specifying H'000001 gives a transfer count of 1, while H'000000 gives the maximum setting,
16,777,216 transfers. During DMAC operation, these registers indicate the remaining number of
transfers.
The upper 8 bits of DMATCR always read 0. The write value, also, should always be 0.
The value after a power-on reset and in standby mode is undefined.
Rev. 3.0, 09/04, page 169 of 1086