Intel 386 - Manual (Page 591)

Intel386™ EX EMBEDDED MICROPROCESSOR USER’S MANUAL
D-26
D.21 DMASRR
DMA Software Request (read format)
DMASRR
Expanded Addr:
ISA Addr:
Reset State: F009H
0009H
00H
7 0
— — — — — — SR1 SR0
Bit
Number
Bit
Mnemonic
Function
7–2 — Reserved. These bits are undefined; for compatibility with future devices,
do not modify these bits.
1 SR1 Software Request 1:
When set, this bit indicates that channel 1 has a software request
pending.
0 SR0 Software Request 0:
When set, this bit indicates that channel 0 has a software request
pending.
DMA Software Request (write format)
DMASRR
Expanded Addr:
ISA Addr:
Reset State: F009H
0009H
00H
7 0
— — — — — SR 0 CS
Bit
Number
Bit
Mnemonic
Function
7–3 — Reserved. These bits are undefined; for compatibility with future devices,
do not modify these bits.
2 SR Software Request:
Setting this bit generates a software request for the channel specified by
bit 0. When the channel’s buffer transfer completes, this bit is cleared.
1 0 Must be 0 for correct operation.
0 CS Channel Select:
0 = The selection for bit 2 affects channel 0.
1 = The selection for bit 2 affects channel 1.