dp83901a National Semiconductor Corporation, dp83901a Datasheet - Page 60

• Manufacturer Part Number: dp83901a
• Description: Serial Network Interface Controller
• Manufacturer: National Semiconductor Corporation

15 0 Switching Characteristics
Note 1 The first port request is issued in response to the remote write command It is subsequently issued on T1 clock cycles following completion of remote
DMA cycles
Note 2 The start of the remote DMA write following WACK is dependent on where WACK is issued relative to BSCK and whether a local DMA is pending
Note 3 Assuming wackw
Note 4 WACK must be high for a minimum of 7 BSCK
Note 5 This is not a measured value but guaranteed by design
Symbol
bprqh
wprql
wackw
bprdl
bprdh
wprq
k
1 BSCK and no local DMA interleave no CS immediate BACK and WACK goes high before T4
Bus Clock to Port Request High (Note 1)
WACK to Port Request Low
WACK Pulse Width
Bus Clock to Port Read Low (Note 2)
Bus Clock to Port Read High
Remote Write Port Request to Port
Request Time (Notes 3 4 5)
Remote DMA (Write Cycle) Recovery Time
Parameter
AC Specs DP83901A Note All Timing is Preliminary (Continued)
60
Min
25
12
Max
42
50
55
40
TL F 10469 – 44
BSCK
Units
ns
ns
ns
ns
ns