AT89LP52-20PU Atmel, AT89LP52-20PU Datasheet - Page 82

• Manufacturer Part Number: AT89LP52-20PU
• Description: IC MCU 8051 8K FLASH SPI 40PDIP
• Manufacturer: Atmel
• Series: 89LPr

Specifications of AT89LP52-20PU

• Core Processor: 8051
• Core Size: 8-Bit
• Speed: 20MHz
• Connectivity: EBI/EMI, I²C, SPI, UART/USART
• Peripherals: Brown-out Detect/Reset, POR, PWM, WDT
• Number Of I /o: 36
• Program Memory Size: 8KB (8K x 8)
• Program Memory Type: FLASH
• Ram Size: 256 x 8
• Voltage - Supply (vcc/vdd): 2.4 V ~ 5.5 V
• Oscillator Type: Internal
• Operating Temperature: -40°C ~ 85°C
• Package / Case: 40-DIP (0.600", 15.24mm)
• Processor Series: AT89x
• Core: 8051
• Data Bus Width: 8 bit
• Data Ram Size: 256 B
• Interface Type: Serial
• Maximum Clock Frequency: 20 MHz
• Number Of Programmable I/os: 36
• Number Of Timers: 3
• Operating Supply Voltage: 2.7 V to 5.5 V
• Maximum Operating Temperature: + 85 C
• Mounting Style: Through Hole
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Eeprom Size: -
• Data Converters: -
• Lead Free Status / Rohs Status: Details

17.3
Figure 17-4. Command Sequence Flow Chart
82
Command Format
AT89LP51/52 - Preliminary
Programming commands consist of an opcode byte, two address bytes, and zero or more data
bytes.
A sample command packet is shown in
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 seri-
ally 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 AT89LP51/52 allocates 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
Figure 17-4 on page 82
Input Address
Input Address
Input Opcode
Input/Output
Byte Mode or
Count == 64
High Byte
Low Byte
yes
Data
shows a simplified flow chart of a command sequence.
no
Figure 17-5 on page
Table 17-2 on page
Address +1
83. The SS pin defines the packet
84.
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