Datasheet

Figure 31-14 Virtual Flash Page Read Register

TDI

TDO

Flash

EEPROM

Fuse s

Lock Bits

STROBES

ADDRESS

Sta te

ma chine

31.10.13. Programming Algorithm

All references below of type “1a”, “1b”, and so on, refer to Table 31-16 JTAG Programming Instruction

Set on page 404.

31.10.14. Entering Programming Mode

1. Enter JTAG instruction AVR_RESET and shift 1 in the Reset Register.

2. Enter instruction PROG_ENABLE and shift 1010_0011_0111_0000 in the Programming Enable

31.10.15. Leaving Programming Mode

1. Enter JTAG instruction PROG_COMMANDS.

2. Disable all programming instructions by using no operation instruction 11a.

3. Enter instruction PROG_ENABLE and shift 0000_0000_0000_0000 in the programming Enable

4. Enter JTAG instruction AVR_RESET and shift 0 in the Reset Register.

31.10.16. Performing Chip Erase

1. Enter JTAG instruction PROG_COMMANDS.

2. Start chip erase using programming instruction 1a.

3. Poll for chip erase complete using programming instruction 1b, or wait for t

WLRH_CE

(refer to table

Command Byte Bit Coding in section Parallel Programming Parameters, Pin Mapping, and

Commands).