AT90PWM2B-16SU View Datasheet(PDF) - Atmel Corporation

Part Name

Description

Manufacturer

AT90PWM2B-16SU

8-bit Atmel Microcontroller with 8K Bytes In-System Programmable Flash

Atmel Corporation 

AT90PWM2/3/2B/3B

25.2 Fuse Bits

The AT90PWM2/2B/3/3B has three Fuse bytes. Table 25-4 - Table 25-6 describe briefly the

functionality of all the fuses and how they are mapped into the Fuse bytes. Note that the fuses

are read as logical zero, “0”, if they are programmed.

Table 25-4. Extended Fuse Byte

Extended Fuse Byte

Bit No Description

Default Value

PSC2RB

7

PSC2 Reset Behaviour

1

PSC1RB

6

PSC1 Reset Behaviour

1

PSC0RB

5

PSC0 Reset Behaviour

1

PSCRV

4

PSCOUT Reset Value

1

–

3

–

1

BOOTSZ1

2

Select Boot Size

(see Table 113 for details)

0 (programmed)(1)

BOOTSZ0

1

Select Boot Size

(see Table 113 for details)

0 (programmed)(1)

BOOTRST

0

Select Reset Vector

1 (unprogrammed)

Note: 1. The default value of BOOTSZ1..0 results in maximum Boot Size. See Table 25-7 on page 285

for details.

25.3 PSC Output Behaviour During Reset

For external component safety reason, the state of PSC outputs during Reset can be pro-

grammed by fuses PSCRV, PSC0RB, PSC1RB & PSC2RB.

These fuses are located in the Extended Fuse Byte (see Table 25-4)

PSCRV gives the state low or high which will be forced on PSC outputs selected by PSC0RB,

PSC1RB & PSC2RB fuses.

If PSCRV fuse equals 0 (programmed), the selected PSC outputs will be forced to high state. If

PSCRV fuse equals 1 (unprogrammed), the selected PSC outputs will be forced to low state.

If PSC0RB fuse equals 1 (unprogrammed), PSCOUT00 & PSCOUT01 keep a standard port

behaviour. If PSC0RB fuse equals 0 (programmed), PSCOUT00 & PSCOUT01 are forced at

reset to low level or high level according to PSCRV fuse bit. In this second case, PSCOUT00 &

PSCOUT01 keep the forced state until PSOC0 register is written.

If PSC1RB fuse equals 1 (unprogrammed), PSCOUT10 & PSCOUT11 keep a standard port

behaviour. If PSC1RB fuse equals 0 (programmed), PSCOUT10 & PSCOUT11 are forced at

reset to low level or high level according to PSCRV fuse bit. In this second case, PSCOUT10 &

PSCOUT11 keep the forced state until PSOC1 register is written.

If PSC2RB fuse equals 1 (unprogrammed), PSCOUT20, PSCOUT21, PSCOUT22 &

PSCOUT23 keep a standard port behaviour. If PSC1RB fuse equals 0 (programmed),

PSCOUT20, PSCOUT21, PSCOUT22 & PSCOUT23 are forced at reset to low level or high

level according to PSCRV fuse bit. In this second case, PSCOUT20, PSCOUT21, PSCOUT22 &

PSCOUT23 keep the forced state until PSOC2 register is written.

4317K–AVR–03/2013

282

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