Datasheet

SAM9G45 [DATASHEET]
Atmel-6438O-ATARM-SAM9G45-Datasheet_08-Dec-15
978
40.5.4.3 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
manually 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.
40.5.4.4 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 40-2, 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.
40.5.4.5 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 buffers is a function of
DMAC_CTRLAx.SRC_DSCR, DMAC_CFGx.SRC_REP, DMAC_CTRLAx.DST_DSCR and
DMAC_CFGx.DST_REP registers.
Table 40-2. 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––11 USR
(1)
2) Multi-buffer transfer with
contiguous DADDR
0–001 LLI
(5)
CONT
(2)
LLI
(5)
3) Multi-buffer transfer with
contiguous SADDR
00–10LLI
(5)
CONT
(2)
LLI
(5)
4) Multi-buffer transfer with
LLI
(5)
support
0––00 LLI
(5)
5) Multi-buffer transfer with
DADDR reloaded
0–101 LLI
(5)
REP
(3)
LLI
(5)
6) Multi-buffer transfer with
SADDR reloaded
01–10LLI
(5)
REP
(3)
LLI
(5)
7) Multi-buffer transfer with
BTSIZE reloaded and
contiguous DADDR
1–001REP
(3)
LLI
(5)
CONT
(2)
LLI
(5)
8) Multi-buffer transfer with
BTSIZE reloaded and
contiguous SADDR
10–10REP
(3)
CONT
(2)
LLI
(5)
9) Automatic mode channel is
stalling, BTSIZE is reloaded
(4)
10011REP
(3)
CONT
(2)
REP
10) Automatic mode BTSIZE,
SADDR and DADDR reloaded
11111 REP
(3)
11) Automatic mode BTSIZE,
SADDR reloaded and DADDR
contiguous
11011REP
(3)
CONT
(2)
REP
(3)