Panasonic JB-3300 Technical Manual page 429

e. Write control signals
(1)
WGT (WRITE-GATE)
This control signal is a HIGH ACTIVE gate signal for all write
operations.
AMW (AM-WRITE)
Also a HIGH ACTIVE signal, this is active when needed for writing
data which include missing blocks (address marks). This signal and
the AEl signal are required simultaneously for writing index marks
on floppy disks.
f. Other input and output related to read operations
(1)
(2)
RDM (RAW-DATA-M)
This is a LOW ACTIVE signal which must be input to acknowledge the
internal SYNC field, and it is the gate signal for the RAW- DATA
bit counter. Consequently, when the SYNC field is set as "00," a
control signal that is at low level during detection of IF cycle
patterns (in MFM mode) or 2F cycle patterns (in FM mode).
DDO, DD1, DD2 (DELAY-DATA O, 1, & 2)
All of the leading edges are risen pulses. Although the raw data
selected by the DS1 signal is fundamentally output as DDO, as long
as there is no DDI] input, the DDO can be a high level signal.
Alghough the DD1 signal is for correcting the width of raw data
and inputs a pulse to delay only the data width portion.
Example: for a 5 Mbit/s disk drive, it inputs a delay of 10 to 25
ns.
'The DD2 Signal is input to the built-in phase comparator. Usually,
the appropriate delay time is half the 4F-CLOCK cycle based on the
DDO signal. ,
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