Seagate Medalist ST31082A, Product Manual

Page: 37 / 92

Host Interface Chapter 5
Technical Reference Manual Page 25
Signal Name: Dir: Pin: Description:
-HOST IO16 I
32
Indication to the host system that the 16-bit data register has
been addressed and that the drive is prepared to send or
receive a 16-bit data word. This line is tri-state line with 24 mA
drive capacity.
-HOST PDIAG I
34
This signal shall be asserted by the slave to the master that it
has completed diagnostics. A 10K ohm pull-up resistor shall be
used on this signal by each drive.
Following a POR, a software reset, or a RESET-, the slave will
negate PDIAG- within 1 ms (to indicate to the master that it is
busy). The slave will then assert PDIAG- within 30 seconds to
indicate that it is no longer busy and is able to provide status.
After the assertion of PDIAG-, the slave may be unable to
accept commands until it has finished its reset procedure and
is ready (DRDY =1).
Following the receipt of a valid Execute Drive Diagnostics
command, the slave will negate PDIAG- within 1 ms to indicate
to the master that it is busy and has not yet passed its drive
diagnostics. If the slave is present, then the master will wait for
up to 5 seconds from the receipt of a valid Execute Drive
Diagnostics command for the slave to assert PDIAG-. The
slave should clear BSY before asserting PDIAG-, as PDIAG- is
used to indicate that the slave has passed its diagnostics and
is ready to post status.
If DASP- was not asserted by the slave during reset
initialization, the master will post its own status immediately
after it completed diagnostics and clear the slave status
register to 00 hex. The master may be unable to accept
commands until it has finished its reset procedure and is
Ready (DRDY = 1).
+HOST
A0,A1,A2 O 35, 33,
36 Bit binary coded address used to select the individual registers
in the task file.
-HOST CS0 O
37
Chip select decoded from the host address bus. Used to select
most of the host-accessible registers.
-HOST CS1 O
38
Chip select decoded from the host address bus. Used to select
three of the registers in the task file.