pc8477b National Semiconductor Corporation, pc8477b Datasheet - Page 49

• Manufacturer Part Number: pc8477b
• Description: Advanced Floppy Disk Controller
• Manufacturer: National Semiconductor Corporation

7 0 Reference Section
These timings are required to support perpendicular recording drives
AC Timings (Continued)
t
t
t
t
t
t
35
36
37
39
41
HDS
1 Mb s
500 kb s
300 kb s
250 kb s
1 Mb s
500 kb s
300 kb s
250 kb s
(t
(t
(t
(t
(t
DST
STD
STP
IW
HDH
– HDSEL Setup to WGATE Active
) – Index Pulse Widh MIN
) – STEP Active Pulse Width
) – DIR Setup to STEP Active MIN
) – DIR Hold from STEP Inactive MIN
) – HDSEL Hold from WGATE Inactive MIN
Description
TABLE 7-1 8477B – 82077AA Parameter Comparison (Continued)
(Continued)
PC8477B
49
t
100
100
100
100
SRT
750
750
750
750
100
6
8
82077AA
no spec
1250
2100
2500
1432
2719
2864
625
716
2 5
10
4
82077SL
no spec
1250
2100
2500
1432
2719
2864
625
716
2 5
10
4
Units
ms
ms
ms
ms
ms
ms
ms
ms
ns
ns
ns
ns