Datasheet

254
7734Q–AVR–02/12
AT90PWM81/161
21.6 Serial Programming Pin Mapping
21.7 Parallel Programming
21.7.1 Enter Programming Mode
The following algorithm puts the device in Parallel (High-voltage) > Programming mode:
1. Set Prog_enable pins listed in Table 21-9 on page 253 to “0000”, RESET pin to “0” and
V
CC
to 0V.
2. Apply 4.5V - 5.5V between V
CC
and GND. Ensure that V
CC
reaches at least 1.8V within
the next 20µs.
3. Wait 20µs - 60µs, and apply 11.5V - 12.5V to RESET.
4. Keep the Prog_enable pins unchanged for at least 10µs after the High-voltage has
been applied to ensure the Prog_enable Signature has been latched.
5. Wait at least 300µs before giving any parallel programming commands.
6. Exit Programming mode by power the device down or by bringing RESET pin to 0V.
If the rise time of the V
CC
is unable to fulfill the requirements listed above, the following alterna-
tive algorithm can be used.
1. Set Prog_enable pins listed in Table 21-9 on page 253 to “0000”, RESET pin to “0” and
V
CC
to 0V.
2. Apply 4.5V - 5.5V between V
CC
and GND.
3. Monitor V
CC
, and as soon as V
CC
reaches 0.9V - 1.1V, apply 11.5V - 12.5V to RESET.
4. Keep the Prog_enable pins unchanged for at least 10µs after the High-voltage has
been applied to ensure the Prog_enable Signature has been latched.
Table 21-12. No. of words in a page and no. of pages in the flash.
Device Flash size Page size PCWORD
No. of
pages PCPAGE PCMSB
AT9 0PWM 81
4K words
(8Kbytes)
32 words PC[4:0] 128 PC[11:5] 11
AT90PWM161
8K words
(16Kbytes)
64 words PC[5:0] 128 PC[12:6] 12
Table 21-13. No. of words in a page and no. of pages in the EEPROM.
Device
EEPROM
size Page size PCWORD
No. of
pages PCPAGE EEAMSB
AT90PWM81/161 512 bytes 4 bytes EEA[1:0] 128 EEA[8:2] 8
Table 21-14. Pin mapping serial programming.
Symbol Pins I/O Description
MOSI I Serial Data in
MISO O Serial Data out
SCK I Serial Clock