Intel 386 - Manual (Page 371)

Intel386™ EX EMBEDDED MICROPROCESSOR USER’S MANUAL
12-36
12.3.6 Status Register (DMASTS)
Use DMASTS to check the status of the channels individually. The DMA sets bits in this register
to indicate that a channel has a hardware request pending or that a channel’s byte count has ex-
pired.
Figure 12-23. DMA Status Register (DMASTS)
DMA Status
DMASTS
(read only) Expanded Addr:
ISA Addr:
Reset State: F008H
0008H
00H
7 0
— — R1 R0 — — TC1 TC0
Bit
Number
Bit
Mnemonic
Function
7–6 — Reserved. These bits are undefined.
5 R1 Request 1:
When set, this bit indicates that channel 1 has a hardware request
pending. When the request is removed, this bit is cleared.
4 R0 Request 0:
When set, this bit indicates that channel 0 has a hardware request
pending. When the request is removed, this bit is cleared.
3–2 — Reserved. These bits are undefined.
1 TC1 Transfer Complete 1:
When set, this bit indicates that channel 1 has completed a buffer
transfer (either its byte count expired or it received an EOP# input).
Reading this register clears this bit and clears TC1 in DMAIS.
0 TC0 Transfer Complete 0:
When set, this bit indicates that channel 0 has completed a buffer
transfer (either its byte count expired or it received an EOP# input).
Reading this register clears this bit and clears TC0 in DMAIS.