S12CPUV2D datasheet(65/138 Pages) MOTOROLA

65 / 138 page

MC9S12DT128 Device User Guide — V02.09

2.3.6 PAD[15] / AN1[7] / ETRIG1 — Port AD Input Pin [15]

PAD15 is a general purpose input pin and analog input of the analog to digital converter ATD1. It can act

as an external trigger input for the ATD1.

2.3.7 PAD[14:8] / AN1[6:0] — Port AD Input Pins [14:8]

PAD14 - PAD8 are general purpose input pins and analog inputs of the analog to digital converter ATD1.

2.3.8 PAD[7] / AN0[7] / ETRIG0 — Port AD Input Pin [7]

PAD7 is a general purpose input pin and analog input of the analog to digital converter ATD0. It can act

as an external trigger input for the ATD0.

2.3.9 PAD[6:0] / AN0[6:0] — Port AD Input Pins [6:0]

PAD6 - PAD8 are general purpose input pins and analog inputs of the analog to digital converter ATD0.

2.3.10 PA[7:0] / ADDR[15:8] / DATA[15:8] — Port A I/O Pins

PA7-PA0 are general purpose input or output pins. In MCU expanded modes of operation, these pins are

used for the multiplexed external address and data bus.

2.3.11 PB[7:0] / ADDR[7:0] / DATA[7:0] — Port B I/O Pins

PB7-PB0 are general purpose input or output pins. In MCU expanded modes of operation, these pins are

used for the multiplexed external address and data bus.

2.3.12 PE7 / NOACC / XCLKS — Port E I/O Pin 7

PE7 is a general purpose input or output pin. During MCU expanded modes of operation, the NOACC

signal, when enabled, is used to indicate that the current bus cycle is an unused or “free” cycle. This signal

will assert when the CPU is not using the bus.

The XCLKS is an input signal which controls whether a crystal in combination with the internal Colpitts

(low power) oscillator is used or whether Pierce oscillator/external clock circuitry is used. The state of this

pin is latched at the rising edge of RESET. If the input is a logic low the EXTAL pin is configured for an

external clock drive. If input is a logic high an oscillator circuit is configured on EXTAL and XTAL. Since

this pin is an input with a pull-up device during reset, if the pin is left floating, the default configuration is

an oscillator circuit on EXTAL and XTAL.

S12CPUV2D Datasheet(PDF) 65 Page - Motorola, Inc