adsp-21161n Analog Devices, Inc., adsp-21161n Datasheet - Page 28

• Manufacturer Part Number: adsp-21161n
• Description: Dsp Microcomputer
• Manufacturer: Analog Devices, Inc.

ADSP-21161N
Memory Write – Bus Master
Use these specifications for asynchronous interfacing to
memories (and memory-mapped peripherals) without reference
to CLKIN. These specifications apply when the ADSP-21161N
is the bus master accessing external memory space in asynchro-
nous access mode.
Table 16. Memory Write – Bus Master
1
2
3
Parameter
Timing Requirements
t
t
t
t
Switching Characteristics
t
t
t
t
t
t
t
t
t
t
W = (number of wait states specified in WAIT register) × t
H = t
HI = t
I = t
ACK Delay/Setup: User must meet t
The falling edge of MSx, BMS is referenced.
See
DAAK
DSAK
SAKC
HAKC
DAWH
DAWL
WW
DDWH
DWHA
DWHD
DATRWH
WWR
DDWR
WDE
Example System Hold Time Calculation on Page 51
CKOP
CKOP
CKOP
WR
DATA
ACK
CLKIN
ADDRESS
MSx, BMS
RD, DMAG
(if a bus idle cycle occurs, as specified in WAIT register; otherwise I = 0).
(if an address hold cycle occurs, as specified in WAIT register; otherwise H = 0).
(if an address hold cycle or bus idle cycle occurs, as specified in WAIT register; otherwise HI = 0).
ACK Delay from Address, Selects
ACK Delay from WR Low
ACK Setup to CLKIN
ACK Hold After CLKIN
Address, Selects to WR Deasserted
Address, Selects to WR Low
WR Pulsewidth
Data Setup Before WR High
Address Hold After WR Deasserted
Data Hold After WR Deasserted
Data Disable After WR Deasserted
WR High to WR, RD, DMAGx Low
Data Disable Before WR or RD Low
WR Low to Data Enabled
DAAK
t
DAWL
t
or t
DAAK
t
DSAK
WDE
1
or t
1
Figure 21. Memory Write – Bus Master
1
SAKC
2
t
DSAK
for calculation of hold times given capacitive and dc loads.
for deassertion of ACK (Low); all three specifications must be met for assertion of ACK (High).
1, 2
2
3
Min
0.5t
1
t
t
t
0.25t
0.25t
0.25t
0.5t
0.25t
–0.25t
t
0.25t
CKOP
CKOP
CKOP
DAWH
–28–
CCLK
CCLK
CKOP
t
SAKC
– 0.25t
– 0.5t
–0.25t
CCLK
CCLK
CCLK
CCLK
CCLK
CCLK
t
.
+3
WW
– 1.25+HI
– 1+H
– 1+H
– 2+H
– 3+I
– 3
t
CCLK
– 1
DDWH
CCLK
CCLK
– 1+W
– 13.5+W
– 3+W
t
HAKC
Max
t
t
0.25t
CKOP
CKOP
–0.5t
–0.75t
CCLK
+2.5+H
CCLK
CCLK
–12+W
t
DWHD
–11+W
t
t
t
DWHA
DATRWH
DDWR
t
WWR
Unit
ns
ns
ns
ns
ns
ns
ns
ns
ns
ns
ns
ns
ns
ns
REV. A