115
ATmega103(L)
0945G–09/01
External Data Memory Timing
Notes:
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.
Table 45.
External Data Memory Characteristics, 4.0 - 6.0 Volts, No Wait State
Symbol
Parameter
6 MHz Oscillator
Variable Oscillator
Unit
Min
Max
Min
Max
0
1/t
CLCL
Oscillator Frequency
0.0
6.0
MHz
1
t
LHLL
ALE Pulse Width
48.3
0.5 t
CLCL
- 35.0
(1)
ns
2
t
AVLL
Address Valid A to ALE Low
43.3
0.5 t
CLCL
- 40.0
(1)
ns
3a
t
LLAX_ST
Address Hold after ALE Low,
ST/STD/STS Instructions
77.3
0.5 t
CLCL
- 10.0
(2)
ns
3b
t
LLAX_LD
Address Hold after ALE Low,
LD/LDD/LDS Instructions
15.0
15.0
ns
4
t
AVLLC
Address Valid C to ALE Low
43.3
0.5 t
CLCL
- 40.0
(1)
ns
5
t
AVRL
Address Valid to RD Low
136.7
1.0 t
CLCL
- 30.0
ns
6
t
AVWL
Address Valid to WR Low
215.0
1.5 t
CLCL
- 35.0
(1)
ns
7
t
LLWL
ALE Low to WR Low
146.7
186.7
1.0 t
CLCL
- 20.0
1.0 t
CLCL
+ 20.0
ns
8
t
LLRL
ALE Low to RD Low
146.7
186.7
0.5 t
CLCL
- 20.0
(2)
0.5 t
CLCL
+ 20.0
(2)
ns
9
t
DVRH
Data Setup to RD High
70.0
70.0
ns
10
t
RLDV
Read Low to Data Valid
136.7
1.0 t
CLCL
- 30.0
ns
11
t
RHDX
Data Hold after RD High
0.0
0.0
ns
12
t
RLRH
RD Pulse Width
146.7
1.0 t
CLCL
- 20.0
ns
13
t
DVWL
Data Setup to WR Low
53.3
0.5 t
CLCL
- 30.0
(2)
ns
14
t
WHDX
Data Hold after WR High
0.0
0.0
ns
15
t
DVWH
Data Valid to WR High
146.7
1.0 t
CLCL
- 20.0
ns
16
t
WLWH
WR Pulse Width
63.3
0.5 t
CLCL
- 20.0
(1)
ns
Table 46.
External Data Memory Characteristics, 4.0 - 6.0 Volts, 1 Cycle Wait State
Symbol
Parameter
6 MHz Oscillator
Variable Oscillator
Unit
Min
Max
Min
Max
0
1/t
CLCL
Oscillator Frequency
0.0
6.0
MHz
10
t
RLDV
Read Low to Data Valid
303.4
2.0 t
CLCL
- 30.0
ns
12
t
RLRH
RD Pulse Width
313.4
2.0 t
CLCL
- 20.0
ns
15
t
DVWH
Data Valid to WR High
313.4
2.0 t
CLCL
- 20.0
ns
16
t
WLWH
WR Pulse Width
230.0
1.5 t
CLCL
- 20.0
(2)
ns