Chain Insertion - Analog Devices ADSP-TS101 TigerSHARC Hardware Reference Manual

DMA Controller Operations

Chain Insertion

A high priority DMA operation or chain can be inserted into an active
DMA chain. In order to do so the current channel transactions must be
stalled by setting the corresponding pause bit in the
DMA chain can be inserted into the current chain without affecting the
current DMA transfer. The new chain is inserted by the TigerSHARC
processor core by writing the
. Once the
DP TCB
data transfer continues from where it left off.
TCB FOR DCD0 SOURCE
DI
DX COUNT DX MODIFY
DY COUNT DY MODIFY
DP CHAIN POINTER
TCB FORDCD0 DESTINATION
DI
DX COUNT DX MODIFY
DY COUNT DY MODIFY
DP CHAIN POINTER
TCB FOR DCD0 SOURCE
DX COUNT
DY COUNT
DP
TCB FO R DCD0 DESTINATION
DX COUNT
DY COUNT
DP
Figure 7-16. DMA Channel 0 Chain Insertion Example
7-44
CHEN
is updated, the
xpause
ONLY THESE TRANSMITTER AND
RECEIVER TCB CONTENTS NEED
BE LOADED MANUALLY TO TCB
TO REGISTERS
PAUSE THIS DMA CHANNEL. READ THE DMA
TCB TRANSMIT AND RECEI VE REGISTERS.
MODIFY THE CHTG AND CHPT FIELDS AND
WRITE BACK TO DMA TCB TRANSMIT AND
RECEIVE REGISTERS. UNPAUSE DMA.
DI
DX MODIFY
DY MODIFY
CHAIN POINTER
DI
DX MODIFY
DY MODIFY
CHAIN POINTER
, , and bits in the
CHTG CHPT
bit in register
TCB FO R DCD0 DESTINATION
TCB FOR DCD0 SOURCE
DI
DX COUNT DX MODIFY
DY COUNT DY MODIFY
DP CHAIN POINTER
TCB FO R DCD0 DESTINATION
DI
DX MODIFY
DX COUNT
DY COUNT DY MODIFY
DP CHAIN POINTER
ADSP-TS101 TigerSHARC Processor
register. A new
DCNT
register
TCBx
is reset and the
DCNT
TCB F OR DCD0 SOURCE
DI
DX MODIFY
DX COUNT
DY COUNT DY MODIFY
DP CHAIN POINTER
DI
DX COUNT
DX MODIFY
DY COUNT DY MODIFY
DP CHAIN POINTER
TCB FOR DCD0 SOURCE
DI
DX CO UNT DX MODIFY
DY CO UNT DY MODIFY
DP CHAI N POINTER
TCB FOR DCD0 DESTINATION
DI
DX CO UNT DX MODIFY
DY CO UNT DY MODIFY
DP CHAI N POINTER
Hardware Reference