ADSP21020 AD [Analog Devices], ADSP21020 Datasheet - Page 17

• Manufacturer Part Number: ADSP21020
• Description: 32/40-Bit IEEE Floating-Point DSP Microprocessor
• Manufacturer: AD [Analog Devices]

REV. C
External Memory Three-State Control
Parameter
Timing Requirement:
t
t
t
Switching Characteristic:
t
t
NOTES
*DT = t
xTS should only be asserted (low) during an active memory access cycle.
Memory Interface = PMA23-0, PMD47-0, PMS1-0, PMRD, PMWR, PMPAGE, DMA31-0, DMD39-0, DMS3-0, DMRD, DMWR, DMPAGE.
Address = PMA23-0, DMA31-0. Select = PMS1-0, DMS3-0.
x = PM or DM.
STS
DADTS
DSTS
DTSD
DTSAE
CK
xTS, Setup before CLKIN High
xTS Delay after Address, Select
xTS Delay after XRD, XWR Low
Memory Interface Disable before
CLKIN High
xTS High to Address, Select Enable
– 50 ns.
PMTS, DMTS
ADDRESS,
xRD, xWR
SELECTS
CLKIN
DATA
t
DADTS
t
Figure 9. External Memory Three-State Control
DSTS
K/B/T Grade K/B/T Grade B/T Grade
Min
14
0
0
20 MHz
t
t
STS
DTSD
Max
50
28
16
Min
12
–2
0
25 MHz
–17–
Max
40
19
11
Min Max Min Max Min
10
–4
0
t
DTSAE
30 MHz
33
13
7
t
STS
9
–5
0
33.3 MHz Frequency Dependency*
K Grade
30
10
6
14 + DT/4 t
DT/4
ADSP-21020
Max
28 + 7DT/8 ns
16 + DT/2
CK
Unit
ns
ns
ns
ns