ISD94100 Series Technical Reference Manual
Sep 9, 2019
Page
268
of 928
Rev1.09
IS
D
9
410
0
S
ER
IE
S
T
E
C
HN
ICA
L
RE
F
E
RE
NCE
M
AN
U
AL
DSCT15
DSCT14
.
.
.
DSCT_CTL
0
1
LSB 16 bits
without [1:0]
MSB 16 bits
SRAM
Load the information to
the channel 15 descriptor table
Current DSCT Entry
Next DSCT Entry
DSCT1
DSCT0
DSCT_NEXT
DSCT_DA
DSCT_SA
DSCT_NEXT
DSCT_DA
DSCT_SA
DSCT_CTL
PDMA_SCATBA
Figure 6.6-4 Descriptor Table Link List Structure
The above link list table operation is DSCT state in Scatter-Gather Mode as shown in Figure 6.6-5.
When loading the information is finished, it will go to transfer state and start transfer by this
information automatically. However, if the next PDMA information is also in the Scatter-Gather
mode, the hardware will catch the next PDMA information block when the current task is finished.
The Scatter-Gather mode stops until the PDMA controller operation mode switch to basic mode
and transfer once or directly switch to idle state.
Idle State
Transfer State
DSCT State
OPMODE (PDMA_DSCTn_CTL[1:0])=0x1
OPMODE (PDMA_DSCTn_CTL[1:0])=0x0
OPMODE (PDMA_DSCTn_CTL[1:0])=0x2
Transfer done
AHB ready
Next Entry
OPMODE
(PDMA_DSCTn_CTL[1:0])=0x0
Figure 6.6-5 Scatter-Gather Mode Finite State Machine