| VSS vcc P1.O-P1.2 P3.O-P3.7 RST X1 X2 AVCC1 AVSS1 ZIN YIN XIN XYZRAMP DECOUPLE VREG XYDACBIAS XYSOURCE ZDAC XYDAC | 8 22 21, 23, 24 24 23 1 -4, 25-28 3 1 4 2 5 7 6 14 13 9 10 11 12 15 16 17 18 19 20 | I I I/O I o I/O I I I I I I o I I I I I 0 o o 0 o 0 o | Circuit Ground Potential. Supply voltage during normal,idle, and power-down operation. Port l: Porl l is a 3-bit bidirectional l/0 porl with internal pull-ups on Pl .0 and Pl .1 . Porl l pins that have ls written to them can be used as inputs. As inputs, port l pins that are externally pulled low will source current because of the inlernal pull-ups (P1 .0, P1 .1). (See DC Electrical Characteristics: IlL). Port l also serves the special function features listed below (Note: P1.0 does not have the strong pullup that is on for 2 0scillator periods.): INTO (P1.0): External interrupt 0. CEX (P1.1): PCA clock output. Port 3: Port 3 is an 8-bit bidirectional l/0 port with internal pull-ups. Port 3 pins that have ls written to them are pulled high by the internal pull-ups and can be used as inputs. As inputs, porl 3 pins that are externally being pulled low will source current because of the pull-ups. (See DC Electrical Characteristics: IlL). (Note: P3.5 does not have the strong pullup that is on for 2 0scillator periods.) Porl 3 also serves the special function as listed below: ECI (P3.6): External PCA clock input. RxD/TO (P3.4): Serial port receiver data input. Timer O external clock input. INTl: External interrupt l. TxD/T1 (P3.5): Serial port transmitter data. Timer l external clock input. Reset: A high on this pin for two machine cycles while the oscillator is running resets the device. (NOTE: The TPM754 does not have an internal reset resislor.) Crystal l : Input to the inverting oscillator amplifier and input to the internal clock generator circuits. Crystal 2: Output from the inverting oscillator amplifier. Analog supply voltage and reference input. Analog supply and reference ground. ZIN: Input to analog multiplexer. YIN: Input to analog multiplexer. XIN: Input to analog multiplexer. XYZRAMP: Provides a low impedance pulldown to VSS under S/W control. DECOUPLE: Output from regulated supply for connection of decoupling capacitors. VREG: Provides regulated analog supply output. XYDACBIAS: Provides source voltage for bias of external circuitry. XYSOURCE: Provides source voltage from regulated analog supply. ZDAC: Switchable output from the internal DAC. XYDAC: Non-switchable output from the internal DAC. |
