DOUBLE DENSITY FORMAT

TYPE III COMMAND WRITE TRACK

~~~~~ n ____ _

^REPEATED

I.

FOR EACH SECTOR -I

~---ID F I E L D - - - ' ~---DATA F I E L D - - - "

WRITEGATE

-L __

SINGLE DENSITY FORMAT

INDEX _ _ _ _ _ REPEATED ~ I

PULSE FOR EACH SECTOR

I"

~---IDFIELD---~

WRITE GATE - - - - -....

DOUBLE DENSITY FORMAT

USER DATA 256 BYTES

L -__________ DATA FIELD---'

OO·xLL~aM

256 BYTES/SECTOR

Shown below is the recommended dual-density for-mat with 256 bytes/sector. In order to forfor-mat a diskette the user issues the Write Track Command and loads the Data Register with the following values.

For every byte to be written, there is one data request.

NUMBER

**Continue Writing until WD177X-00 interrupts out.

Approx. 668 bytes.

1. Non-Standard Formats

Variations in the recommended formats are possible to a limited extent if the following requirements are met: lengths are as short as 2 bytes for WD177X-OO opera-tion, however PLL lock up time, motor speed varia-tion, write-splice area, etc. adds more bytes to each gap to achieve proper operation. For highest system reliability use the recommended format.

FM MFM

**Byte counts are minimum, except exactly 3 bytes of A 1 must be written.

STATUS REGISTER DESCRIPTION (WD1770-00 and WD1772-00 only)

BIT NAME MEANING

STATUS REGISTER SUMMARY (WD1773-00 only)

ALL TYPE I READ READ READ WRITE WRITE

BIT COMMANDS ADDRESS SECTOR TRACK SECTOR TRACK

S7 NOT READY NOT READY NOT READY NOT READY NOT READY NOT READY

S6 WRITE 0 0 0 WRITE WRITE

PROTECT PROTECT PROTECT

S5 HEAD LOADED 0 RECORD TYPE 0 WRITE FAULT WRITE FAULT

S4 SEEK ERROR RNF RNF 0 RNF 0

S3 CRC ERROR CRC ERROR CRC ERROR 0 CRC ERROR 0

S2 TRACK 0 LOST DATA LOST DATA LOST DATA LOST DATA LOST DATA

S1 INDEX PULSE DRO DRO DRO DRO DRO

SO BUSY BUSY BUSY BUSY BUSY BUSY

STATUS FOR TYPE I COMMANDS (WD1773-00 only)

BIT NAME MEANING

S7 NOT READY This bit when set. indicates the drive is not ready. When reset it indicates that the drive is ready. This bit is an inverted copy of the Ready input and logically "ORed"

with MR.

S6 PROTECTED When set, indicates Write Protect is activated. This bit is an inverted copy of WRPT input.

S5 HEAD LOADED When set, it indicates the head is loaded and engaged. This bit is a logical "and"

of HLD and HLT signals.

S4 SEEK ERROR When set, the desired track was not verified. This bit is reset to 0 when updated.

S3 CRC ERROR CRC encountered in ID field.

S2 TRACK 00 When set, indicates Read/Write head is positioned to Track O. This bit is an inverted copy of the TROO input.

S1 INDEX WheJlset, indicates index mark detected from drive. This bit is an inverted copy of the IP input.

SO BUSY When set, command is in progress. When reset no command is in progress.

STATUS FOR TYPE II AND III COMMANDS (WD1773-00 ONLy)

BIT NAME MEANING

S7 NOT READY This bit when set indicates the drive is not ready. When reset, it indicates that the drive is ready. This bit is an inverted copy of the Ready input and "ORed" with MR.

The Type II and III Commands will not execute unless the drive is ready.

S6 WRITE PROTECT On Read Record: Not Used. On Read Track: Not Used. On any Write: It indicates a Write Protect. This bit is reset when updated.

S5 RECORD TYPE On Read Record: It indicates the record-type code from data field address mark.

1 = Deleted Data Mark. 0 = Data Mark. On any Write: Forced to a Zero.

S4 RECORD NOT When set, it indicates that the desire track, sector, or side were not found. This bit FOUND (RNF) is reset when updated.

S3 CRC ERROR If S4 is set, an error is found in one or more ID fields; otherwise it indicates error in data field. This bit is reset when updated.

S2 LOST DATA When set, it indicates the computer did not respond to DRO in one byte time. This bit is reset to zero when updated.

S1 DATA REOUEST This bit is a copy of the DRO output. When set, it indicates the DR is full on a Read Operation or the DR is empty on a Write operation. This bit is reset to zero when updated.

SO BUSY When set, command is under execution. When reset, no command is under execution.

Floppy Disk Controller Devices 1-19

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DC ELECTRICAL CHARACTERISTICS MAXIMUM RATINGS

NOTE Storage Temperature ... 55°C (67°F) to

Maximum limits indicate where permanent device damage occurs. Continuous operation at these limits is not intended and should be limited to those con-ditions specified in the DC Operating Characteristics.

+ 125°C (257°F)

Operating Temperature ... 0oC (32°F) to 70°C (158°F) Ambient

Maximum Voltage to Any Input

with Respect to V ss ... + 7V to -0.5V DC OPERATING CHARACTERISTICS

=

0°C(32°F) to 70°C (158°F), Vss

=

^{OV, Vee}

=

^+5V^±^.25V

SYMBOL CHARACTERISTIC MIN MAX UNITS CONDITIONS

IlL Input Leakage 10 JJA VIN

=

^Vee

IOL Output Leakage 10 JJA VOUT

=

Vee

VIH Input High Voltage 2.0 V

VIH Input Low Voltage 0.8 V

VOH Output High Voltage 2.4 V 10

=

^{-100 JJA}

VOL Output Low Voltage 0.40 V 10 = 1.6 mA

Po Power Dissipation .75 W

Rpu Internal Pull-Up 100 1700 JJA VIN

=

^OV

lee Supply Current 75(Typ) 150 rnA

AC TIMING CHARACTERISTICS

=

OOC (32°F) to 70°C (158°F), vss

=

^{OV, vCC}

=

^{+ 5V}^±^.25V

g~LS _________ --; _ ~x ^VALID X'-___ _

~'DV_1 r-'DOH~

R/W _ _

--J/~I

-~I\\...----cs ----~I~~\

^{- t}^RE

7 . ) 1

-... f - - - t O R R - - - . - t · 1

ORQ

\'---READ ENABLE TIMING READ ENABLE TIMING - RE such that: R/W = 1, CS = O.

SYMBOL CHARACTERISTIC MIN TYP MAX UNITS CONDITIONS

tRE RE Pulse Width of CS 200 nsec CL

=

^{50 pf}

tORR ORO Reset from RE 200 300 nsec

tov Data Valid from RE 100 200 nsec CL

=

^{50 pf}

tOOH Data Hold from RE 20 150 nsec CL

=

^{50 pf}

INTRa Reset from RE 8 JJsec

Note: ORO and INTRa reset are from rising edge (lagging) of RE, whereas resets are from falling edge (leading) of WE. Worst ease service time for ORO is 23.5 JJsec for MFM and 47.5 JJsec for FM.

X

^VALID

X

DALS 0-7

i ~'DS±'DH~

I

^Cs

~

^tWE ^{; { '}

'SET=j ~ ^/;='HLD

RiiN

'\ Y

tAS

-1

1'-

^{t A H 1}

t

AO,A1

I

ORO ""- tDRW

~

WRITE ENABLE TIMING

WRITE ENABLE TIMING - WE such that: R/W

=

^{0, CS}

=

SYMBOL CHARACTERISTIC MIN TYP MAX UNITS CONDITIONS

tAS Setup ADDR to CS 50 nsec

tSET Setup RIW to CS _ 0 nsec

tAH Hold ADDR from CS 10 nsec

tHLD Hold RlW from CS 0 nsec

tWE WE Pulse Width 200 nsec

tORW ORO Reset from WE 100 200 nsec

tos Data Setup to WE 150 nsec

tOH Data Hold from WE 0 nsec

I NTRO Reset from WE 8 J.lsec

READ DATA TIMING:

CHARACTERISTIC MIN TYP MAX UNITS CONDITIONS

Raw Read Pulse Width .200 3 J.lsec MFM

.400 3 FM

Raw Read Cycle Time 3 J.lsec

Floppy Disk Controller Devices 1-21

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Dans le document Products 1986 (Page 42-47)

DOUBLE DENSITY FORMAT

TYPE III COMMAND WRITE TRACK