at89c51re2-slsem ATMEL Corporation, at89c51re2-slsem Datasheet - Page 50

• Manufacturer Part Number: at89c51re2-slsem
• Description: At89c51re2 8-bit Flash Microcontroller
• Manufacturer: ATMEL Corporation

Operation Cross Memory Access
50
AT89C51RE2
or BANK3
boot RM0
External
memory
EA = 0
FM0
Space addressable in read and write are:
•
•
•
•
•
•
•
•
The table below provide the different kind of memory which can be accessed from differ-
ent code location.
Table 26. Cross Memory Access
RAM
ERAM (Expanded RAM access by movx)
XRAM (eXternal RAM)
FM0 ( user flash )
Hardware byte
XROW FM0
Boot RM0
Flash Column latch
Action
Read
Read
Read
Write
Write
Write
RAM
ok
ok
ok
ok
ok
ok
XRAM
ERAM
ok
ok
ok
ok
ok
ok
boot RM0
ok
-
-
-
-
-
ok (RWW)
ok (idle)
FM0
ok
ok
-
-
ok (RWW)
HSB
ok
ok
ok
-
-
ok (RWW)
FCB
ok
ok
ok
-
-
7663B–8051–03/07
XAF FM0
ok (RWW)
ok
ok
ok
-
-