ATmega16HVB datasheet(188/273 Pages) ATMEL

188 / 273 page

188

8042A–AVR–07/09

ATmega16HVB/32HVB

• Bit 6 - TWBCIE: TWI Bus Connect/Disconnect Interrupt Enable

When the TWBCIE bit and the I-bit in the Status Register are set, the TWI Bus Connect/Discon-

ne ct In terr upt is e nab le d. Th e corre spon ding inte rrup t is execu t ed if a TWI Bus

Connect/Disconnect occurs, i.e., when the TWBCIE bit is set.

• Bit 5:3 - Res: Reserved Bits

These bits are reserved bits in the ATmega16HVB/32HVB and will always read as zero.

• Bit 2:1 - TWBDT1, TWBDT0: TWI Bus Disconnect Time-out Period

The TWBDT bits decides how long both the TWI data (SDA) and clock (SCL) signals must be

low before generating the TWI Bus Disconnect Interrupt. The different configuration values and

their corresponding time-out periods are shown in Table 27-8.

• Bit 0 - TWBCIP: TWI Bus Connect/Disconnect Interrupt Polarity

The TWBCIP bit decide if the TWI Bus Connect/Disconnect Interrupt Flag (TWBCIF) should be

set on a Bus Connect or a Bus Disconnect. If TWBCIP is cleared, the TWBCIF flag is set on a

Bus Connect. If TWBCIP is set, the TWBCIF flag is set on a Bus Disconnect.

Table 27-8.

TW Bus Disconnect Time-out Period

TWBDT1

TWBDT0

TWI Bus Disconnect Time-out Period

250 ms

500 ms

1000 ms

2000 ms

ATmega16HVB Datasheet(PDF) 188 Page - ATMEL Corporation