VT82C686B
UltraDMA-33 / 66 / 100 Enhanced IDE Interface
Signal Name
Pin #
I/O Signal Description
/
N16
I
EIDE Mode:
UltraDMA Mode:
Device ready indicator
PDRDY
Primary I/O Channel Ready.
. Output flow control. The device
Primary Device DMA Ready
PDDMARDY /
PDSTROBE
may assert DDMARDY to pause output transfers
. Input data strobe (both edges). The
Primary Device Strobe
device may stop DSTROBE to pause input data transfers
/
V20
N17
W19
N18
I
EIDE Mode:
UltraDMA Mode:
Device ready indicator
SDRDY
Secondary I/O Channel Ready.
SDDMARDY /
SDSTROBE
.
Output flow control. The
Secondary Device DMA Ready
device may assert DDMARDY to pause output transfers
. Input data strobe (both edges). The
device may stop DSTROBE to pause input data transfers
Device read strobe
. Primary channel input flow control
The host may assert HDMARDY to pause input transfers
. Output data strobe (both edges). The
host may stop HSTROBE to pause output data transfers
Device read strobe
. Input flow control. The host
may assert HDMARDY to pause input transfers
Secondary Device Strobe
/
O
O
O
EIDE Mode:
UltraDMA Mode:
PDIOR#
PHDMARDY /
PHSTROBE
Primary Device I/O Read.
Primary Host DMA Ready
.
Primary Host Strobe
/
EIDE Mode:
UltraDMA Mode:
SDIOR#
Secondary Device I/O Read.
Secondary Host DMA Ready
SHDMARDY /
SHSTROBE
. Output strobe (both edges). The host may stop
HSTROBE to pause output data transfers
Host Strobe B
/
/
EIDE Mode:
UltraDMA Mode:
Device write strobe
Stop transfer: Asserted by the host prior to
initiation of an UltraDMA burst; negated by the host before data
is transferred in an UltraDMA burst. Assertion of STOP by the
host during or after data transfer in UltraDMA mode signals the
termination of the burst.
PDIOW#
Primary Device I/O Write.
.
Primary Stop
PSTOP
W20
O
EIDE Mode:
Device write strobe
SDIOW#
Secondary Device I/O Write.
SSTOP
UltraDMA Mode:
. Stop transfer: Asserted by the host prior to
Secondary Stop
initiation of an UltraDMA burst; negated by the host before data
is transferred in an UltraDMA burst. Assertion of STOP by the
host during or after data transfer in UltraDMA mode signals the
termination of the burst.
N19
Y20
M20
V19
L1
I
I
O
O
I
Primary channel DMA request
Secondary channel DMA request
PDDRQ
SDDRQ
PDDACK#
SDDACK#
IRQ14
Primary Device DMA Request.
Secondary Device DMA Request.
Primary Device DMA Acknowledge.
Secondary Device DMA Acknowledge.
Primary Channel Interrupt.
Primary channel DMA acknowledge
Secondary channel DMA acknowledge
K5
I
IRQ15
Secondary Channel Interrupt.
Revision 1.71 June 9, 2000
-12-
Pinouts
ETC [ ETC ]
