atmega161-4pi ATMEL Corporation, atmega161-4pi Datasheet - Page 133

• Manufacturer Part Number: atmega161-4pi
• Description: 8-bit Microcontroller With 16k Bytes Of In-system Programmable Flash
• Manufacturer: ATMEL Corporation

External Data Memory Timing
Table 51. External Data Memory Characteristics, 4.0 - 5.5 Volts, No Wait State
Notes:
Table 52. External Data Memory Characteristics, 4.0 - 5.5 Volts, 1 Cycle Wait State
1228D–AVR–02/07
0
1
2
3a
3b
4
5
6
7
8
9
10
11
12
13
14
15
16
0
10
12
15
16
Symbol
1/t
t
t
t
t
t
t
t
t
t
t
t
t
t
t
t
t
t
Symbol
1/t
t
t
t
t
LHLL
AVLL
LLAX_ST
LLAX_LD
AVLLC
AVRL
AVWL
LLWL
LLRL
DVRH
RLDV
RHDX
RLRH
DVWL
WHDX
DVWH
WLWH
RLDV
RLRH
DVWH
WLWH
1. This assumes 50% clock duty cycle. The half period is actually the high time of the external clock, XTAL1.
2. This assumes 50% clock duty cycle. The half period is actually the low time of the external clock, XTAL1.
CLCL
CLCL
Parameter
Oscillator Frequency
Read Low to Data Valid
RD Pulse Width
Data Valid to WR High
WR Pulse Width
Parameter
Oscillator Frequency
ALE Pulse Width
Address Valid A to ALE Low
Address Hold After ALE Low,
write access
Address Hold after ALE Low,
read access
Address Valid C to ALE Low
Address Valid to RD Low
Address Valid to WR Low
ALE Low to WR Low
ALE Low to RD Low
Data Setup to RD High
Read Low to Data Valid
Data Hold After RD High
RD Pulse Width
Data Setup to WR Low
Data Hold After WR High
Data Valid to WR High
WR Pulse Width
22.5
22.5
42.5
42.5
27.5
27.5
Min
105
105
Min
230
220
230
95
10
15
95
95
60
95
8 MHz Oscillator
0
8 MHz Oscillator
Max
145
145
65
Max
185
0.5t
0.5t
0.5t
0.5t
0.5t
0.5t
1.0t
1.0t
1.0t
1.0t
1.0t
1.0t
2.0t
2.0t
2.0t
CLCL
CLCL
CLCL
CLCL
CLCL
CLCL
Min
CLCL
CLCL
CLCL
CLCL
CLCL
CLCL
0.0
10
15
60
0
Variable Oscillator
Min
CLCL
CLCL
CLCL
0.0
-40
-40
-20
-20
-35
-35
Variable Oscillator
-30
-30
-30
-20
-30
-20
-20
-30
-20
(1)
(1)
(2)
(2)
(1)
(1)
ATmega161(L)
0.5t
0.5t
2.0t
CLCL
CLCL
Max
Max
8.0
CLCL
65
8.0
+20
+20
-65
(2)
(2)
Unit
MHz
ns
ns
ns
ns
ns
ns
ns
ns
ns
ns
ns
ns
ns
ns
ns
ns
ns
MHz
Unit
ns
ns
ns
ns
133