
Programmable Four-Channel Communications Controller
—
CD2481
Datasheet
205
10.6
AC Electrical Characteristics (
Revisions B and D at 60 MHz
)
Symbol
Parameter
(Sheet 1 of 2)
MIN
MAX
t
PERIOD
Period of CLK input (60 MHz maximum)
16.667
t
LOW
CLK low phase (60/40 duty cycle, worst case)
6.667
10
t
HIGH
CLK high phase (60/40 duty cycle, worst case)
6.667
10
t
1
CLK high to BUSCLK high
17
t
2
CLK high to BUSCLK low
17
Bus Arbitration
t
11
CLK high to BGACK* tristate
25
t
12
BGIN* low to address valid
1
40
t
13
Address hold after CLK high
0
t
14
CLK high to address tristate
20
t
15
CLK high to ADLD* low
13
t
16
CLK high to ADLD* high
16
t
17
Address setup to ADLD* high
15
t
18
CLK high to AEN*/DATEN*/DATDIR* high
20
t
19
CLK high to AEN*/DATEN*/DATDIR* tristate
20
t
20
CLK high to AEN*/DATEN*/DATDIR* low
25
DMA Read
t
21
t
22
t
23
t
24
t
25
t
26
t
27
t
28
t
29
Data setup to CLK high
2
Data hold after CLK high
12
CLK high to address valid
27
CLK low to AS* low
16
CLK high to AS* high
15
CLK low to DS* low
16
CLK high to DS* high
15
DTACK* low setup to CLK high
10
DTACK* high setup to CLK high (to avoid false termination)
30
DMA Write
t
31
t
32
t
33
t
34
t
35
t
36
CLK high to data valid
40
Data hold after CLK high
0
CLK low to DS* low
16
CLK high to DS* high
15
DTACK* low setup to CLK high
10
DTACK* high setup to CLK high (to avoid false termination)
30
Host Read/Write
t
41
DS* and CS* low setup to CLK high
7