Datasheet

20
8042ES–AVR–09/2013
ATmega16HVB/32HVB
11.2 The Atmel ATmega32HVB
11.2.1 Rev. E
TWI bus can get stuck if TWI STOP condition bit is set in slave mode
If the TWSTO bit in TWCR is set while the TWI starts to receive data in slave mode, it can result
in pulling the SCL pin low and then the TWI bus will get stuck. To release the SCL pin and get
out of this situation the TWI module needs to be disabled and then re-enabled.
Problem fix/workaround
While in slave mode the TWSTO bit should be written only to recover from an error condition and
then cleared before a data transfer starts.
11.2.2 Rev. D
Not sampled.
11.2.3 Rev. C
TWI bus can get stuck if TWI STOP condition bit is set in slave mode
If the TWSTO bit in TWCR is set while the TWI starts to receive data in slave mode, it can result
in pulling the SCL pin low and then the TWI bus will get stuck. To release the SCL pin and get
out of this situation the TWI module needs to be disabled and then re-enabled.
Problem fix/workaround
While in slave mode the TWSTO bit should be written only to recover from an error condition and
then cleared before a data transfer starts.
11.2.4 Rev. B
TWI bus can get stuck if TWI STOP condition bit is set in slave mode
If the TWSTO bit in TWCR is set while the TWI starts to receive data in slave mode, it can result
in pulling the SCL pin low and then the TWI bus will get stuck. To release the SCL pin and get
out of this situation the TWI module needs to be disabled and then re-enabled.
Problem fix/workaround
While in slave mode the TWSTO bit should be written only to recover from an error condition and
then cleared before a data transfer starts.
11.2.5 Rev. A
Not sampled.