gm82c765b ETC-unknow, gm82c765b Datasheet - Page 15

• Manufacturer Part Number: gm82c765b
• Description: Floppy Disk Subsystem Controller
• Manufacturer: ETC-unknow

TABLE 4. STATUS REGISTER 1 BITs
#D4
#D3
TABLE 3. STATUS REGISTER 0 BITs
NO
NO
D7
D6
D5
D2
D1
D0
D7
D6
D5
D4
D3
D2
D1
END OF
CYCLINDER
DATA ERROR
OVERRUN
NOT DATA
NO DATA
NOT
WRITEABLE
UNIT SELECT 1
UNIT SELECT 0
HEAD SELECT
EQUIPMENT
NOT READY
INTERRUPT
SEEK END
CHECK
NAME
NAME
CODE
BIT
BIT
SYMBOL
SYMBOL
US1
US0
NR
EC
HS
NW
SE
ND
EN
DE
OR
IC
D7 = 0 and D6 = 0, Normal termination of command was completed
properly executed.
D7 = 0 and D6 = 1, Abnormal termination of command (AT).
Execution of command was started but was not successfully completed.
D7 = 1 and D6 = 0.
Invalid comand issue, (IC). Command which was issued was never
started.
When FDC completes the SEEK comand, this flag is set to 1 (HIGH)
If the Track 0, signal fails to occur after 255 step pulses (Recalibrate
command). Then this flag is set.
Since drive ready is always persumed true. This will always be a LOGIC
0.
This flag is used to indicate the state of HEAD at interrupt
This flag is used to indicate a DRIVE UNIT Number at interrupt
This flag is used to indicate a DRIVE UNIT Number at interrupt
When the FDC tries to access a sector beyond the final sector of a
cylinder,this flag is set.
Not used. This bit is always 0 (low)
When the FDC detects a * CRC error in either the ID field or a cylinder,
this flag is set.
If the FDC is not serviced by the host system during data transfers within
a certain time interval, this flag is set.
Not used. This bit is always 0 (low)
During execution of READ DATA, WRITE DELETED DATA, or SCAN
command, if the FDC cannot find the sector specified in the * * IDR
Register, this flag is set. During execution of the READ ID command, if
the FDC cannot read the ID field without an error, then this flag is set.
During execution of the READ A TRACK command, if the starting sector
cannot be found, then this flag is set.
During execution of WRITE DATA, WRITE DELETED DATA or
RORMAT A TRACK commands. If the FDC detects a WP signal from
the FDC, then this flag is set.
15
DESCRIPTION
DESCRIPTION
GM82C765B