ADSP-BF50x Blackfin Processor Hardware Reference
7-87
Direct Memory Access
Handshake MDMA Current Edge Count Registers
(HMDMAx_ECOUNT)
The
HMDMAx_ECOUNT
register, shown in
Figure 7-21
, holds a signed number
of edges remaining to be serviced. This number is in a signed two’s com-
plement representation. When an edge is detected on the respective
DMARx
input, requests occur if this count is greater than or equal to 0 and
BCOUNT
is greater than 0.
When the handshake mode is enabled,
ECOUNT
is loaded and the resulting
number of requests is:
Number of edges + N
where N is the number loaded from
ECINIT
. The number N can be posi-
tive or negative. Examples:
• 0x7FFF = 32,767 edges remaining
• 0x0000 = 0 edges remaining
• 0x8000 = –32,768: ignore the next 32,768 edges
Each time that
BCOUNT
expires,
ECOUNT
is decremented and
BCOUNT
is
reloaded from
BCINIT
. When a handshake request edge is detected,
ECOUNT
is incremented. The
ECOUNT
field is cleared when
HMDMA
is disabled.
Figure 7-20. Handshake MDMA Current Block Count Registers
0
0
0
0
0
0
15 14
13 12
11 10
9
8
7
6
5
4
3
2
1
0
0
0
0
0
0
0
0
0
0
0
Handshake MDMA Current Block Count Register (HMDMAx_BCOUNT)
BCOUNT[15:0] (Transfers
Remaining for Current Edge)
Reset = 0x0000
Содержание EZ-KIT Lite ADSP-BF506F
Страница 50: ...Contents l ADSP BF50x Blackfin Processor Hardware Reference ...
Страница 92: ...Development Tools 1 30 ADSP BF50x Blackfin Processor Hardware Reference ...
Страница 110: ...Interface Overview 3 12 ADSP BF50x Blackfin Processor Hardware Reference ...
Страница 132: ...Unique Information for the ADSP BF50x Processor 4 22 ADSP BF50x Blackfin Processor Hardware Reference ...
Страница 236: ...Internal Flash Memory Control Registers 6 92 ADSP BF50x Blackfin Processor Hardware Reference ...
Страница 342: ...Unique Information for the ADSP BF50x Processor 7 106 ADSP BF50x Blackfin Processor Hardware Reference ...
Страница 484: ...Unique Information for the ADSP BF50x Processor 10 60 ADSP BF50x Blackfin Processor Hardware Reference ...
Страница 493: ...ADSP BF50x Blackfin Processor Hardware Reference 11 9 Core Timer Unique Information for the ADSP BF50x Processor None ...
Страница 494: ...Unique Information for the ADSP BF50x Processor 11 10 ADSP BF50x Blackfin Processor Hardware Reference ...
Страница 506: ...Unique Information for the ADSP BF50x Processor 12 12 ADSP BF50x Blackfin Processor Hardware Reference ...
Страница 544: ...Unique Information for the ADSP BF50x Processor 13 38 ADSP BF50x Blackfin Processor Hardware Reference ...
Страница 650: ...Programming Examples 15 56 ADSP BF50x Blackfin Processor Hardware Reference ...
Страница 712: ...Unique Information for the ADSP BF50x Processor 16 62 ADSP BF50x Blackfin Processor Hardware Reference ...
Страница 804: ...Programming Examples 17 92 ADSP BF50x Blackfin Processor Hardware Reference ...
Страница 972: ...Unique Information for the ADSP BF50x Processor 20 38 ADSP BF50x Blackfin Processor Hardware Reference ...
Страница 1194: ...Programming Examples 24 90 ADSP BF50x Blackfin Processor Hardware Reference ...
Страница 1256: ...ACM Registers A 50 ADSP BF50x Blackfin Processor Hardware Reference ...
Страница 1264: ...Boundary Scan Architecture B 8 ADSP BF50x Blackfin Processor Hardware Reference ...