AT89LP51ED2 Atmel Corporation, AT89LP51ED2 Datasheet - Page 217

• Manufacturer Part Number: AT89LP51ED2
• Manufacturer: Atmel Corporation

Specifications of AT89LP51ED2

• Flash (kbytes): 64 Kbytes
• Max. Operating Frequency: 20 MHz
• Cpu: 8051-1C
• Max I/o Pins: 42
• Spi: 1
• Twi (i2c): 1
• Uart: 1
• Adc Channels: 7
• Adc Resolution (bits): 10
• Adc Speed (ksps): 153.8
• Sram (kbytes): 2.25
• Eeprom (bytes): 4096
• Self Program Memory: API
• Operating Voltage (vcc): 2.4 to 5.5
• Timers: 4
• Isp: SPI/OCD/UART
• Watchdog: Yes

24.6.2
Figure 24-19. Command Sequence Flow Chart
3714A–MICRO–7/11
Command Format
Programming commands consist of two preamble bytes, an opcode byte, two address bytes,
and zero or more data bytes.
mand sequence.
A sample command packet is shown in
packet frame. SS must be brought low before the first byte in a command is sent and brought
back high after the final byte in the command has been sent. The command is not complete until
SS returns high. Command bytes are issued serially on MOSI. Data output bytes are received
serially on MISO. Packets of variable length are supported by returning SS high when the final
required byte has been transmitted. In some cases command bytes have a don’t care value.
Don’t care bytes in the middle of a packet must be transmitted. Don’t care bytes at the end of a
packet may be ignored.
Page oriented instructions always include a full 16-bit address. The higher order bits select the
page and the lower order bits select the byte within that page. The AT89LP51RD2/ED2/ID2 allo-
cates 6 bits for byte address, 1 bit for low/high half page selection and 9 bits for page address.
The half page to be accessed is always fixed by the page address and half select as transmitted.
The byte address specifies the starting address for the first data byte. After each data byte has
been transmitted, the byte address is incremented to point to the next data byte. This allows a
page command to linearly sweep the bytes within a page. If the byte address is incremented
past the last byte in the half page, the byte address will roll over to the first byte in the same half
page. While loading bytes into the page buffer, overwriting previously loaded bytes will result in
data corruption.
For a summary of available commands, see
Input Preamble 1
Input Preamble 2
Input Address
Input Address
Input Opcode
Input/Output
High Byte
Low Byte
(AAh)
(55h)
Data
AT89LP51RD2/ED2/ID2 Preliminary
Figure 24-19 on page 217
Figure 24-20 on page
Address +1
Table 24-20 on page
shows a simplified flow chart of a com-
218. The SS pin defines the
219.
217