Programming Algorithm
All references below of type “1a”, “1b”, and so on, refer to Table 116.
1. Enter JTAG instruction AVR_RESET and shift 1 in the Reset Register.
Entering Programming Mode
2. Enter instruction PROG_ENABLE and shift 1010_0011_0111_0000 in the Pro-
gramming Enable Register.
Leaving Programming Mode
1. Enter JTAG instruction PROG_COMMANDS.
2. Disable all programming instructions by usning no operation instruction 11a.
3. Enter instruction PROG_ENABLE and shift 0000_0000_0000_0000 in the pro-
gramming Enable Register.
4. Enter JTAG instruction AVR_RESET and shift 0 in the Reset Register.
Performing Chip Erase
Programming the Flash
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 112 on page 269).
Before programming the Flash a Chip Erase must be performed. See “Performing Chip
Erase” on page 284.
1. Enter JTAG instruction PROG_COMMANDS.
2. Enable Flash write using programming instruction 2a.
3. Load address high byte using programming instruction 2b.
4. Load address low byte using programming instruction 2c.
5. Load data using programming instructions 2d, 2e and 2f.
6. Repeat steps 4 and 5 for all instruction words in the page.
7. Write the page using programming instruction 2g.
8. Poll for Flash write complete using programming instruction 2h, or wait for tWLRH
(refer to Table 112 on page 269).
9. Repeat steps 3 to 7 until all data have been programmed.
A more efficient data transfer can be achieved using the PROG_PAGELOAD
instruction:
1. Enter JTAG instruction PROG_COMMANDS.
2. Enable Flash write using programming instruction 2a.
3. Load the page address using programming instructions 2b and 2c. PCWORD
(refer to Table 106 on page 258) is used to address within one page and must be
written as 0.
4. Enter JTAG instruction PROG_PAGELOAD.
5. Load the entire page by shifting in all instruction words in the page, starting with
the LSB of the first instruction in the page and ending with the MSB of the last
instruction in the page.
6. Enter JTAG instruction PROG_COMMANDS.
7. Write the page using programming instruction 2g.
8. Poll for Flash write complete using programming instruction 2h, or wait for tWLRH
(refer to Table 112 on page 269).
9. Repeat steps 3 to 8 until all data have been programmed.
284
ATmega32(L)
2503J–AVR–10/06
ATMEL [ ATMEL ]
