Table of Contents
Advertisement
DMA Registers
A block done interrupt is generated when
bit in the
MBDI
until
is 0. Note if
ECOUNT
ated, since no DMA requests were generated or grants received.
Handshake MDMA Current Block Count Register (HMDMAx_BCOUNT)
HMDMA0:
0xFFC0 3318
HMDMA1:
0xFFC0 3358
Figure 5-21. Handshake MDMA Current Block Count Registers
HMDMAx_ECOUNT Registers
The handshake MDMA current edge count register (
shown in
Figure
serviced. This number is in a signed two's complement representation. An
edge is detected on the respective
is greater than or equal to 0, and
When the handshake mode is enabled,
number of requests is:
Number of edges + N
where
is the number loaded from
N
or negatively signed number. Examples:
• 7FFF = 32767 edges remaining
• 0000 = 0 edges remaining
• 8000 = –32768: ignore the next 32768 edges
5-102
register is set, the interrupt is suppressed
HMDMAx_CONTROL
BCINIT
15 14 13 12 11 10
9
8
0
0
0
0
0
0
0
0
5-22, holds a signed number of edges remaining to be
,
ADSP-BF537 Blackfin Processor Hardware Reference
decrements to 0. If the
BCOUNT
is 0, no block done interrupt is gener-
7
6
5
4
3
2
1
0
0
0
0
0
0
0
input. Requests occur if this count
DMARx
is greater than 0.
BCOUNT
is loaded and the resulting
ECOUNT
. The number
ECINIT
0
Reset = 0x0000
0
BCOUNT[15:0] (Transfers
Remaining for Current Edge)
,
HMDMAx_ECOUNT)
is a positively
N
Advertisement
Table of Contents
