T89C51AC2-SLSIM View Datasheet(PDF) - Atmel Corporation
Part Name
Description
MFG CO.
'T89C51AC2-SLSIM' PDF : 121 Pages View PDF
Operation Cross Memory Access
Space addressable in read and write are:
• RAM
• ERAM (Expanded RAM access by movx)
• XRAM (eXternal RAM)
• EEPROM DATA
• FM0 (user flash)
• Hardware byte
• XROW
• Boot Flash
• Flash Column latch
The table below provide the different kind of memory which can be accessed from differ-
ent code location.
Table 27. Cross Memory Access
Action
RAM
boot FLASH
Read
Write
FM0
Read
Write
External
memory
EA = 0
or Code Roll
Over
Read
Write
Note: 1. RWW: Read While Write
XRAM
ERAM
Boot FLASH
OK
-
OK
-
-
-
FM0
OK
OK(1)
OK
OK (idle)
-
-
E² Data
OK
OK(1)
OK
OK(1)
OK
OK(1)
Hardware
Byte
OK
OK(1)
OK
-
-
-
XROW
-
OK(1)
-
OK
-
-
44 A/T89C51AC2
4127H–8051–02/08
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