ATmega32A Datasheet - Sunrom Technologies

ATmega32A• SDA – Port C, Bit 1SDA, Two-wire Serial Interface Data: When the TWEN bit in TWCR is set (one) to enable theTwo-wire Serial Interface, pin PC1 is disconnected from the port and becomes the Serial DataI/O pin for the Two-wire Serial Interface. In this mode, there is a spike filter on the pin to suppressspikes shorter than 50 ns on the input signal, and the pin is driven by an open drain driverwith slew-rate limitation. When this pin is used by the Two-wire Serial Interface, the pull-up canstill be controlled by the PORTC1 bit.• SCL – Port C, Bit 0SCL, Two-wire Serial Interface Clock: When the TWEN bit in TWCR is set (one) to enable theTwo-wire Serial Interface, pin PC0 is disconnected from the port and becomes the Serial ClockI/O pin for the Two-wire Serial Interface. In this mode, there is a spike filter on the pin to suppressspikes shorter than 50 ns on the input signal, and the pin is driven by an open drain driverwith slew-rate limitation. When this pin is used by the Two-wire Serial Interface, the pull-up canstill be controlled by the PORTC0 bit.Table 12-10 and Table 12-11 relate the alternate functions of Port C to the overriding signalsshown in Figure 12-5 on page 56.Table 12-10.Overriding Signals for Alternate Functions in PC7:PC4SignalName PC7/TOSC2 PC6/TOSC1 PC5/TDI PC4/TDOPUOE AS2 AS2 JTAGEN JTAGENPUOV 0 0 1 0DDOE AS2 AS2 JTAGEN JTAGENDDOV 0 0 0 SHIFT_IR + SHIFT_DRPVOE 0 0 0 JTAGENPVOV 0 0 0 TDODIEOE AS2 AS2 JTAGEN JTAGENDIEOV 0 0 0 0DI – – – –AIO T/C2 OSC OUTPUT T/C2 OSC INPUT TDI –8155C–AVR–02/1163