AT89LP4052 Atmel Corporation, AT89LP4052 Datasheet - Page 75

• Manufacturer Part Number: AT89LP4052
• Manufacturer: Atmel Corporation

Specifications of AT89LP4052

• Flash (kbytes): 4 Kbytes
• Max. Operating Frequency: 20 MHz
• Cpu: 8051-1C
• Max I/o Pins: 15
• Spi: 1
• Uart: 1
• Sram (kbytes): 0.25
• Operating Voltage (vcc): 2.4 to 5.5
• Timers: 2
• Isp: SPI
• Watchdog: Yes

23.5.2
23.5.3
3547J–MICRO–10/09
Power-down Sequence
ISP Start Sequence
Execute this sequence to power-down the device after serial programming.
Figure 23-23. Serial Programming Power-down Sequence
Note:
Execute this sequence to enter ISP when the device is already operational.
Figure 23-24. In-System Programming (ISP) Start Sequence
1. Tri-state MOSI (P1.5).
2. Bring SCK (P1.7) to “L”.
3. Bring RST to “L”.
4. Bring SS (P1.4) to “L”
5. Power off Vcc.
1. Bring SS (P1.4) to “H”.
2. Tri-state MISO (P1.6).
3. Bring RST to “H”.
4. Bring SCK (P1.7) to “L”.
The waveforms on this page are not to scale.
XTAL1
MISO
MOSI
MISO
MOSI
SCK
RST
RST
SCK
V
V
SS
SS
CC
CC
HIGH Z
AT89LP2052/LP4052
HIGH Z
HIGH Z
HIGH Z
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