GM82C765 View Datasheet(PDF) - Hynix Semiconductor
Part Name
Description
Manufacturer
GM82C765 Datasheet PDF : 36 Pages
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GM82C765B
TABLE 4. STATUS REGISTER 1 BITs
BIT
NO
NAME
D0 MISSING
ADDRESS
MARK
SYMBOL
DESCRIPTION
MA If the FDC cannot detect the ID Address Mark after encountering the
index hole twice, then this flag is set.
If the FDC cannot detect the Data Address Mark or Deleted Data Address
Mark, this flag is set. At the same time the MD (Missing Address Mark in
data field) of Status Register 2 is set.
TABLE 5. STATUS REGISTER 2 BITs
BIT
NO
NAME
SYMBOL
DESCRIPTION
D7
Not Used. This bit is always 0 (low)
D6 CONTROL
CM
During executing of the READ DATA or SCAN Command, if the FDC
MARK
encounters a sector which contains a Deleted Data Address Mark, this flag
is set.
D5 DATA ERROR DD
If the FDC detects a CRC error in the data field, then this flag is set.
D4 WRONG
WC
This bit is related to the ND bit, and when the contents of * * * C on the
CYLINDER
medium is different from that stored in the IDR, this flag is set.
D3 SCAN EQUAL SH
During execution of the SCAN command, if the condition of “equal” is
satisfied this flag is set.
D2 SCAN NOT
SN
During execution of the SCAN command, if the FDC cannot find a sector
on the cylinder which meets the condition, then this flag is set.
D1 BAD
BC
This bit is related to the ND bit, and when the contents of C on the
CYLINDER
medium is different from that stored in the IDR, and the contents of C is
FF, then this flag is set.
D0 MISSING
MD
When data is read from the medium, if the FDC cannot find a Data
ADDRES
Address Mark or Deleted data Address Mark, then this flag is set.
MARK
IN DATA FIELD
TABLE 6. STATUS REGISTER 3 BITs
BIT
NO
NAME
SYMBOL
DESCRIPTION
#D7
Not used. Will always be logic 0.
D6 WRITE
PROTECTED
WP This bit is used to indicate the status of the WRITE PROTECTED
signal from the FDD
#D5 READY
D4 TRACK 0
#D3 WRITE
PROTECTED
RY
This bit will always be a logic 1.
Drive is presumed to be ready.
TO This bit is used to indicate the status of the Track 0 signal from the FDD.
WP
This bit is used to indicate the status of the WRITE PROTECTED
signal from the FDD
D2 HEAD SELECT
HS This bit is used to indicate the status of the Side Select signal to the FDD
D1 UNIT SELECT 1
CYLINDER
US1
This bit is used to indicate the status of the Unit Select 1 signal to the
FDD
D0 UNIT SELECT 2
US0
This bit is used to indicate the status of the Unit Select 0 signal to the
FDD
Note : *
CRC - Cyclic Redundancy Check
**
IDR - internal Data Register
* * * C - Cylinder
#
- Different from NEC765
16
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