276
ATmega16M1/32M1/64M1 [DATASHEET]
8209E–AVR–11/2012
Note:
27.3
PSC output behavior during reset
For external component safety reason, the state of PSC outputs during Reset can be programmed by fuses
PSCRB, PSCARV & PSCBRV.
If PSCRB fuse equals 1 (unprogrammed), all PSC outputs keep a standard port behaviour. If PSC0RB fuse equals
0 (programmed), all PSC outputs are forced at reset to low level or high level according to PSCARV and PSCBRV
fuse bits. In this second case, the PSC outputs keep the forced state until POC register is written.
See “POC – PSCPSCARV (PSCOUTnA Reset Value) gives the state low or high which will be forced on PSCOUT0A, PSCOUT1A,
and PSCOUT2A outputs when PSCRB is programmed. If PSCARV fuse equals 0 (programmed), the PSCOUT0A,
PSCOUT1A, and PSCOUT2A outputs will be forced to high state. If PSCRV fuse equals 1 (unprogrammed), the
PSCOUT0A, PSCOUT1A, and PSCOUT2A outputs will be forced to low state.
PSCBRV (PSCOUTnB Reset Value) gives the state low or high which will be forced on PSCOUT0B, PSCOUT1B,
and PSCOUT2B outputs when PSCRB is programmed. If PSCBRV fuse equals 0 (programmed), the PSCOUT0B,
PSCOUT1B and PSCOUT2B outputs will be forced to high state. If PSCRV fuse equals 1 (unprogrammed), the
PSCOUT0B, PSCOUT1B, and PSCOUT2B outputs will be forced to low state.
2
Brown-out detector trigger
level
1 (unprogrammed)
1
Brown-out detector trigger
level
1 (unprogrammed)
0
Brown-out detector trigger
level
1 (unprogrammed)
Table 27-4.
Extended Fuse byte. (Continued)
Extended Fuse byte
Bit no.
Description
Default value
Table 27-5.
PSC output behavior during and after reset until POC register is written.
PSCRB
PSCARV
PSCBRV
PSCOUTnA
PSCOUTnB
unprogrammed
X
normal port
programmed
unprogrammed
forced low
programmed
unprogrammed
programmed
forced low
forced high
programmed
unprogrammed
forced high
forced low
programmed
forced high
2
Brown-out detector
trigger level
1 (unprogrammed)
1
Brown-out detector
trigger level
1 (unprogrammed)
0
Brown-out detector
trigger level
1 (unprogrammed)