at89lp2052-20xi ATMEL Corporation, at89lp2052-20xi Datasheet - Page 68

• Manufacturer Part Number: at89lp2052-20xi
• Description: At89lp2052 8-bit Microcontroller With 2/4-kbyte Flash
• Manufacturer: ATMEL Corporation

23.4.11
23.4.12
68
AT89LP2052/LP4052
Write Lock Bits
Read Lock Bits
Function:
Usage:
Figure 23-15. Write Lock Bits Sequence
Function:
Usage:
Figure 23-16. Read Lock Bits Sequence
Note:
• Program (lock) Lock Bits 1 and 2.
1. Bring CS (P3.2) low.
2. Drive P1 to AAh and pulse XTAL1 high.
3. Drive P1 to E4h 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 Lock Bits 1 and 2.
1. Bring CS (P3.2) low.
2. Drive P1 to 0xAA and pulse XTAL1 high.
3. Drive P1 to 0x64 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
The waveforms on this page are not to scale.
P1
CS
P1
AAh
AAh
E4h
00h
64h
00h
00h
111111LL
00h
111111LL
3547H–MICRO–5/07