Owner manual

Rev. F - 15 February, 2001 76
T89C51RD2
9.5.2. External Program Memory Characteristics
Table 38. Symbol Description
Symbol Parameter
T Oscillator clock period
T
LHLL
ALE pulse width
T
AVLL
Address Valid to ALE
T
LLAX
Address Hold After ALE
T
LLIV
ALE to Valid Instruction In
T
LLPL
ALE to PSEN
T
PLPH
PSEN Pulse Width
T
PLIV
PSEN to Valid Instruction In
T
PXIX
Input Instruction Hold After PSEN
T
PXIZ
Input Instruction FloatAfter PSEN
T
AVIV
Address to Valid Instruction In
T
PLAZ
PSEN Low to Address Float
Table 39. AC Parameters for a Fix Clock
Symbol -M -L Units
Min Max Min Max
T 25 25 ns
T
LHLL
40 40 ns
T
AVLL
10 10 ns
T
LLAX
10 10 ns
T
LLIV
70 70 ns
T
LLPL
15 15 ns
T
PLPH
55 55 ns
T
PLIV
35 35 ns
T
PXIX
0 0 ns
T
PXIZ
18 18 ns
T
AVIV
85 85 ns
T
PLAZ
10 10 ns