Texas Instruments MSP430x4xx - Manual (Page 171)

8-11
Figure 8−5. DMA Burst-Block Transfer State Diagram
2 x MCLK
Reset
Wait for Trigger
Idle
Hold CPU,
Transfer one word/byte
Burst State
(release CPU for 2xMCLK)
[+Trigger AND DMALEVEL = 0 ]
OR
[Trigger=1 AND DMALEVEL=1]
DMAABORT=0
DMAABORT = 1
2 x MCLK
DMAEN = 0
Modify T_SourceAdd
Modify T_DestAdd
Decrement DMAxSZ
[DMADTx = {6, 7}
AND DMAxSZ = 0]
[ENNMI = 1
AND NMI event]
OR
[DMALEVEL = 1
AND Trigger = 0]
[DMADTx = {2, 3}
AND DMAxSZ = 0]
OR
DMAEN = 0
DMAxSZ
→
T_Size
DMAxSA
→
T_SourceAdd
DMAxDA
→
T_DestAdd
T_Size → DMAxSZ
DMAxSA → T_SourceAdd
DMAxDA
→
T_DestAdd
DMAEN = 0
DMAEN = 1
DMAxSZ > 0
DMAxSZ > 0 AND
a multiple of 4 words/bytes
were transferred
DMAxSZ > 0
DMAEN = 0
DMAREQ = 0
T_Size
→
DMAxSZ