AT89C51RB2/RC2
External Program Memory
Read Cycle
12 TCLCL
TLHLL
TLLIV
TLLPL
ALE
TPLPH
PSEN
TPXAV
TPXIZ
TLLAX
TAVLL
TPLIV
TPLAZ
TPXIX
INSTR IN
PORT 0
PORT 2
INSTR IN
A0-A7
A0-A7
INSTR IN
TAVIV
ADDRESS A8-A15
ADDRESS
OR SFR-P2
ADDRESS A8-A15
External Data Memory
Characteristics
Table 78. Symbol Description
Symbol
TRLRH
TWLWH
TRLDV
TRHDX
TRHDZ
TLLDV
Parameter
RD Pulse Width
WR Pulse Width
RD to Valid Data In
Data Hold After RD
Data Float After RD
ALE to Valid Data In
Address to Valid Data In
ALE to WR or RD
Address to WR or RD
TAVDV
TLLWL
TAVWL
TQVWX
TQVWH
TWHQX
TRLAZ
TWHLH
Data Valid to WR Transition
Data set-up to WR High
Data Hold After WR
RD Low to Address Float
RD or WR High to ALE high
113
4180E–8051–10/06
ATMEL [ ATMEL ]
