AT89C51CC03C-RLTIM View Datasheet(PDF) - Atmel Corporation
Part Name
Description
MFG CO.
AT89C51CC03C-RLTIM Datasheet PDF : 197 Pages
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AT89C51CC03
FM0 Memory Architecture
User Space
Extra Row (XRow)
Hardware security Byte (HSB)
The Flash memory is made up of 4 blocks (see Figure 23):
• The memory array (user space) 64K Bytes
• The Extra Row
• The Hardware security bits
• The column latch registers
This space is composed of a 64K Bytes Flash memory organized in 512 pages of 128
Bytes. It contains the user’s application code.
This row is a part of FM0 and has a size of 128 Bytes. The extra row may contain infor-
mation for boot loader usage.
The Hardware security Byte space is a part of FM0 and has a size of 1 byte.
The 4 MSB can be read/written by software (from FM0 and , the 4 LSB can only be read
by software and written by hardware in parallel mode.
H Hardware Security Byte (HSB)
7
6
5
4
X2
BLJB
-
-
3
2
1
0
-
LB2
LB1
LB0
Bit
Bit
Number Mnemonic Description
X2 Mode
7
X2
Programmed (=’0’) to force X2 mode (6 clocks per instruction) after reset
Unprogrammed to force X1 mode, Standard Mode, afetr reset (Default)
Boot Loader Jump Bit
When unprogrammed (=’1’), at the next reset :
-ENBOOT=0 (see code space memory configuration)
6
BLJB -Start address is 0000h (PC=0000h)
When programmed (=’0’)at the nex reset:
-ENBOOT=1 (see code space memory configuration)
-Start address is F800h (PC=F800h)
5
-
Reserved
4
-
Reserved
3
-
Reserved
General Memory Lock Bits (only programmable by programmer tools)
2-0
LB2-0
Section “Flash Protection from Parallel Programming”, page 54
Column Latches
The column latches, also part of FM0, have a size of full page (128 Bytes).
The column latches are the entrance buffers of the three previous memory locations
(user array, XROW and Hardware security byte). The column latches are write only and
can be accessed only from FM1 (boot mode) and from external memory
Cross Flash Memory Access
Description
The FM0 memory can be program only from FM1. Programming FM0 from FM0 or from
external memory is impossible.
The FM1 memory can be program only by parallel programming.
The Table show all software Flash access allowed.
45
4182K–CAN–05/06
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