AT89S8253 Atmel Corporation, AT89S8253 Datasheet - Page 40

• Manufacturer Part Number: AT89S8253
• Manufacturer: Atmel Corporation

Specifications of AT89S8253

• Flash (kbytes): 12 Kbytes
• Max. Operating Frequency: 24 MHz
• Cpu: 8051-12C
• Max I/o Pins: 32
• Spi: 1
• Uart: 1
• Sram (kbytes): 0.25
• Eeprom (bytes): 2048
• Operating Voltage (vcc): 2.7 to 5.5
• Timers: 3
• Isp: SPI
• Watchdog: Yes

24. Serial Programming Instruction
The Instruction Set for Serial Programming follows a 4-byte protocol and is shown in
Table 24-1.
After Reset signal is high, SCK should be low for at least 64 system clocks before it goes high to clock in the enable data
bytes. No pulsing of Reset signal is necessary. SCK should be no faster than 1/16 of the system clock at pin XTAL1.
For Page Read/Write, the data always starts from byte 0 to 31 or 63. After the command byte and upper address byte are
latched, each byte thereafter is treated as data until all 32 or 64 bytes are shifted in/out. Then the next instruction will be
ready to be decoded.
40
Instruction
Programming Enable
Chip Erase
Write Program Memory
(Byte Mode)
Read Program Memory
(Byte Mode)
Write Program Memory
(Page Mode)
Read Program Memory
(Page Mode)
Write Data Memory
(Byte Mode)
Read Data Memory
(Byte Mode)
Write Data Memory
(Page Mode)
Read Data Memory
(Page Mode)
Write User Fuses
Read User Fuses
Write Lock Bits
Read Lock Bits
Write User Sgn. Byte
Read User Sgn. Byte
Write User Sgn. Page
Read User Sgn. Page
Read ATMEL Sgn. Byte
AT89S8253
Serial Programming Instruction Set
Byte 1
1010 1100
1010 1100
0100 0000
0010 0000
0101 0000
0011 0000
1100 0000
1010 0000
1101 0000
1011 0000
1010 1100
0010 0001
1010 1100
0010 0100
0100 0010
0010 0010
0101 0010
0011 0010
0010 1000
Byte 2
0101 0011
100x xxxx
xx
xx
xx
xx
xxxx x
xxxx x
xxxx x
xxxx x
0001
xxxx xxxx
1110 0
xxxx xxxx
xxxx xxxx
xxxx xxxx
xxxx xxxx
xxxx xxxx
xxxx xxxx
Instruction Format
Byte 3
xxxx xxxx
xxxx xxxx
xxxx xxxx
xxxx xxxx
xxxx xxxx
xxxx xxxx
xx
xx
xxxx xxxx
xxxx xxxx
xx
00 0000
00 0000
0 0000
0 0000
Byte 4
xxxx xxxx
xxxx xxxx
xxxx xxxx
xxxx
xxxx xxxx
xxxx x
Byte 0 ... Byte 63
Byte 0 ... Byte 63
Byte 0 ... Byte 31
Byte 0 ... Byte 31
Byte 0 ... Byte 63
Byte 0 ... Byte 63
Byte n
Table
24-1.
Operation
Enable Serial Programming while
RST is high
Chip Erase both the 12K and 2K
memory arrays
Write data to Program Memory –
Byte Mode
Read data from Program Memory –
Byte Mode
Write data to Program Memory –
Page Mode (64 bytes)
Read data from Program Memory –
Page Mode (64 bytes)
Write data to Data Memory
– Byte Mode
Read data from Data Memory – Byte
Mode
Write data to Data Memory – Page
Mode (32 bytes)
Read data from Data Memory
– Page Mode (32 bytes)
Write user fuse bits (refer to next
page for the fuse definitions)
Read back status of user fuse bits
Write the lock bits (write a “0” to
lock)
Read back current status of the lock
bits (a programmed lock bit reads
back as a “0”)
Read Signature Byte
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