Rainbow Electronics AT91CAP9S250A - Manual (Page 287)

287
6264A–CAP–21-May-07
AT91CAP9S500A/AT91CAP9S250A
26.3.4.3 Programming DMAC for Multiple Buffer Transfers
Notes: 1. USR means that the register field is manually programmed by the user.
2. CONT means that address are contiguous.
3. REP means that the register field is updated with its previous value. If the transfer is the first one, then the user must manu-
ally program the value.
4. Channel stalled is true if the relevant BTC interrupt is not masked.
5. LLI means that the register field is updated with the content of the linked list item.
26.3.4.4 Replay Mode of Channel Registers
During automatic replay mode, the channel registers are reloaded with their initial values at the
completion of each buffer and the new values used for the new buffer. Depending on the row
number in
Table 26-1 on page 287 , some or all of the DMAC_SADDRx, DMAC_DADDRx,
DMAC_CTRLAx and DMAC_CTRLBx channel registers are reloaded from their initial value at
the start of a buffer transfer.
26.3.4.5 Contiguous Address Between Buffers
In this case, the address between successive buffers is selected to be a continuation from the
end of the previous buffer. Enabling the source or destination address to be contiguous between
Table 26-1. Multiple Buffers Transfer Management Table
Transfer Type AUTO SRC_REP DST_REP SRC_DSCR DST_DSCR BTSIZE SADDR DADDR
Other
Fields
1) Single Buffer or Last
buffer of a multiple buffer
transfer
0 – – 1 1 USR USR USR USR
2) Multi Buffer transfer
with contiguous DADDR
0 – 0 0 1 LLI LLI CONT LLI
3) Multi Buffer transfer
with contiguous SADDR
0 0 – 1 0 LLI CONT LLI LLI
4) Multi Buffer transfer
with LLI support
0 – – 0 0 LLI LLI LLI LLI
5) Multi Buffer transfer
with DADDR reloaded
0 – 1 0 1 LLI LLI REP LLI
6) Multi Buffer transfer
with SADDR reloaded
0 1 – 1 0 LLI REP LLI LLI
7) Multi Buffer transfer
with BTSIZE reloaded and
contiguous DADDR
1 – 0 0 1 REP LLI CONT LLI
8) Multi Buffer transfer
with BTSIZE reloaded and
contiguous SADDR
1 0 – 1 0 REP CONT LLI LLI
9) Automatic mode
channel is stalling
BTsize is reloaded
1 0 0 1 1 REP CONT CONT REP
10) Automatic mode
BTSIZE, SADDR and
DADDR reloaded
1 1 1 1 1 REP REP REP REP
11) Automatic mode
BTSIZE, SADDR reloaded
and DADDR contiguous
1 1 0 1 1 REP REP CONT REP