AT89LP4052 Atmel Corporation, AT89LP4052 Datasheet - Page 70

• 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

23.4.13
23.4.14
70
AT89LP2052/LP4052
Write User Fuses
Read User Fuses
Function:
Usage:
Figure 23-17. Write User Fuses Sequence
Function:
Usage:
Figure 23-18. Read User Fuses Sequence
Note:
• Program User Fuses.
• Unimplemented bits should always be written with 1s.
1. Bring CS (P3.2) low.
2. Drive P1 to AAh and pulse XTAL1 high.
3. Drive P1 to E1h and pulse XTAL1 high.
4. Drive P1 to 00h and pulse XTAL1 high.
5. Drive P1 to 00h and pulse XTAL1 high.
6. Drive data on P1 and pulse XTAL1 high.
7. Drive CS high.
8. Wait 4 ms, monitor P3.1, or poll data/status.
• Read status of User Fuses
1. Bring CS (P3.2) low.
2. Drive P1 to 0xAA and pulse XTAL1 high.
3. Drive P1 to 0x61 and pulse XTAL1 high.
4. Drive P1 to 0x00 and pulse XTAL1 high.
5. Drive P1 to 0x00 and bring XTAL1 high.
6. Tri-state P1.
7. Bring XTAL1 low.
8. Read data from P1.
9. Drive CS high.
RDY/BSY
XTAL1
XTAL1
CS
P1
The waveforms on this page are not to scale.
CS
P1
AAh
AAh
E1h
00h
61h
00h
00h
1111FFFF
00h
1111FFFF
3547J–MICRO–10/09