HP 7957A Hardware Manual page 23

Interface Information
7957 A/7958A
INDEX
or
SECTOR
U...j
j...-
o.
8
USEe
II I N
-+l I--
200
: I
(WRITE SPLICE)
I I
J\
NSEC MIN.
WRI TE
GATE
------: .......... 1 :
n
&
:
~.~,---------------------------~
. .
12 BYTES
- - ,
~
FORMAT
ADR ADR
ADDRESS
ADR
ADR WRITE
ISG PLO SYNC CHECK
I
SYNC PATTERN
FIELD BYTES PAD SPLICE
&
WRITE GATE MAY REMAIN ACTIVE DURING THIS TIME.
IESOIA10
Figure 2-2. Write Gate Timing During Format
INDEX
~fCTOR
LJ
FORMAT
READ
GATE
ISG
ADDRESS WRITE DATA DATA
FIELD
SPLICE PLO SYNC
SYNC PATTERN
Jl=100
NSEC MIN
u
DATA
DATA DATA
FIELD CHECK PAD ISG
BYTES
L
WRITE
GATE
------------~I~--------------------------
IESOIA12
Figure 2-3. Write Gate Timing During Normal Write
• READY. This signal is used as defined in the
ESDI specification.
• COMMAND DATA. The following commands
are supported by the drive (refer to table 2-5):
Seek
Recalibrate
Request Status
Request Configuration
Select Head Group
Control (Reset Interface, Stop Spindle
Motor, Start Spindle Motor)
Track Offset
Initiate Diagnostics
All other commands and reserved command
codes are treated as illegal commands.
• TRANSFER REQUEST. The TRANSFER
REQUEST handshake timing is shown in figure
2-5.
• ADDRESS MARK ENABLE. This signal is not
used. The drive will ignore any activity on this
line.
• TRANSFER
TRANSFER
ACKNOWLEDGE. The
ACKNOWLEDGE handshake
timing is shown in figure 2-5.
2-7