AT89S4D12-12JC Ver la hoja de datos (PDF) - Atmel Corporation
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AT89S4D12-12JC Datasheet PDF : 13 Pages
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Once the bytes of a sector are loaded into the device, they
are simultaneously programmed during the self-timed pro-
gramming cycle (tWC). After the first data byte has been
loaded into the device, successive bytes need to be
entered within 300-µs time intervals. If a Page Write
instruction is not detected in 300-µs after the last write
instruction, the load period will end and the internal pro-
gramming cycle will start.
Address bits A7 - A11 and A7 - A16 specify the sector
address of the Code and Data memory arrays, respec-
tively. The valid sector address must be entered during
each write instruction. Address bits A0 - A6 specify the byte
address within the sector. The bytes may be loaded in any
order, sequential loading is not required. Once a program-
ming operation has been initiated, and for a duration of typ-
ically 5 ms, a read operation will effectively be a polling
operation.
Program Verify
If lock bits LB1 and LB2 have not been programmed, the
programmed Code and Data byte can be read back via
serial output pin SDO. The state of the lock bits can only be
verified indirectly by observing that the lock bit features are
enabled.
Serial Programming Instruction Set
Instruction
Byte 1
Byte 2
Format
Byte 3
Programming
Enable
10101100 01010011
11111111
Chip Erase
10101100 10000000
xxxxxxxx
Read Code
Memory
0010000x
xxxx
Page Write Code
Memory
0100000x
xxxx
Read Data
Memory
1010000
Page Write Data
Memory
1100000
Program Lock Bits 10101100 111000
xxxxxxxx
Read Signature
0011000x
xxxxxxxx
x
Notes:
1. A16:A0 = Memory byte address
2. ‘DDDDDDDD’ = Data input at pin SDI or data output
at pin SDO.
3. ‘x’ = Don’t care.
Byte 4
11111111
xxxxxxxx
DDDDDDDD
DDDDDDDD
DDDDDDDD
DDDDDDDD
xxxxxxxx
DDDDDDDD
Operation
Enable Serial
Programming
after RST goes high.
Chip erase both 128K &
4K
memory arrays.
Read data at pin SDO for
Code memory at
address
A11:A0.
Write data at pin SDI for
Code
memory at address
A11:A0.
Read data at pin SDO for
Data memory at address
A16:A0.
Write data at pin SDI for
Data
memory at address
A16:A0.
Set LB1, LB2 = ‘0’ to
program
lock bits.
Read device I.D. at
address
A6:A0.
4-290
AT89S4D12
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