Tandy 1000 HX Technical Reference Manual page 205

M
PD765A//iPD7265
NEC
AC Characteristics (cont)
T
A
= -10°Cto +70°C, V
c c
= +5V ±5% unless otherwise specified
765A, 726S
Parameter Symbol Min Typ(1) R
Umito
lax M
765A-2,7265-2
In iyp(1) Max Unit
Tatt
Window cycle time
twcv
4
2
2
1
2
4
2
2
1
2
M
s
M
S
M
S
M S
M S
MFM = 0,51/4"
MFM = 1.5V4"
MFM = 0, 8"
MFM = 1, 8"
MFM = 0,3i/2" (3)
Window hold time to ROD
Window hold time from RDD
US
Oi
1 hold time to RW / seek t
RW/seek hold time to low
current/direction t
Low current / direction hold time to
fault reset/stept
US
0
1 hold time from fault reset/
step'1
Step active time (high)
Step cycle time
Fault reset active time (high)
Write data width
USo, 1 hold time after seek
Seek hold time from DIR
DIR hold time after step
Index pulse width
RDI delay from DRQ
WR 4 delay from DRQ
WE or RD response time from DRQ t
tRDW
tWRD
tus
tso
tDST
*STU
tSTP
tsc
tFR
l
WDD
tsu
tDS
tSTD
t|DX
tMR
tMW
tMRW
15
15
12
7
1.0
5.0
6
33
8.0
t
O
-5O
15
30
24
4
800
250
1
15
15
12
7
1.0
5.0
7 8 6
(Note 2) (Note 2) 33
10 8.0
to-50
15
30
24
4
800
250
12
1
7 8
(Note 2) (Note 2)
10
12
M
s
ns
ns
M S
M S
M S
M S
M S
M S
M S
ns
M S
M S
M S
<D
C Y
ns
ns
M S
MFM = 1,3V2"(3)
8 MHz clock period(4)
8MHzclockperiod(4)
8 MHz clock period(4)
8MHzclockperiod(4)
(Note 4)
(Note 4)
(Note A)
8MHzclockperiod(4)
8 MHz clock period(4)
8MHzclockpenod(4)
8MHzclockperiod(4)
8MHzclockperiod(4)
8MHzclockperiod(4)
Note:
(1) Typical values for T
A
= 25°C and nominal supply voltage.
(2) Under software control. The range is from 1 ms to 16 ms at 8 MHz clock period, and 2 ms to 32 ms at 4 MHz clock period.
(3) Sony Micro Floppydisk 31/2" drive.
(4) Double these values for a 4 MHz clock period.
Timing Waveforms
Processor Read Operation Processor Write Operation