Analog Devices ADSP-21261 SHARC Hardware Reference Manual page 315

• Chain Pointer registers (
hold the starting address of the TCB (parameter register values) for
the next DMA operation on the corresponding channel. These reg-
isters also control whether the I/O processor generates an interrupt
when the current DMA process ends.
• External Index register (
memory address, acting as a pointer to the next external memory
DMA read or write location.
• External Modify registers (
increment by which the DMA controller post-modifies the corre-
sponding external memory index register after the DMA read or
write.
• External Count registers (
the number of words remaining to be transferred to or from exter-
nal memory on the corresponding DMA channel.
Table 7-4. ADSP-2126x Processor DMA Channel Parameter Registers
Register Function
IIy Internal Index Register
IMxy Internal Modify Register
Cxy Internal Count Register
CPxy Chain Pointer Register
EIPP External Index Register
EMPP External Modify Register
ECPP External Count Register
1 IDP_DMA_Mx are 6 bits wide only.
ADSP-2126x SHARC Processor Hardware Reference
, ). Chain pointer registers
CPSPx CPSPI
). Index register provides an external
EIPP
). Modify registers provide the
EMPPx
). External count registers indicate
ECPPx
Width Description
19 bits Address of buffer in internal
memory
1 Stride for internal buffer
16 bits
16 bits Length of internal buffer
20 bits Chain pointer for DMA
chaining
19 bits Address of buffer in external
memory
2 bits Stride for external buffer
16 bits Length of external buffer
I/O Processor
7-25