Functional Overview

MAC7100 Microcontroller Family Product Brief, Rev. 2

Preliminary

Freescale Semiconductor

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4.6

Port Integration Module (PIM)

The Port Integration Module (PIM) provides the interface between the physical pins and either the general

purpose I/O signals or the various peripherals which provide alternate signal functions. MAC7100 devices

implement up to 9 ports, each of which is up to 16-bits wide (all pins are not available in some packages).

Each pin can be independently configured to be either in port mode or peripheral mode. When peripheral

mode is selected, the pin’s output and configuration are both controlled by the peripheral module. Each pin

is also capable of being used as an interrupt source with a filter available to help eliminate instances of

noise-generated false interrupts. For some devices, GPIO Port H is available rather than Port C; the PIM

enables swapping of Port H and Port C in the address map to assist transparent porting of code between

various devices. Following a reset into any mode other than normal or secured expanded mode, all pins are

configured as general purpose inputs. Following a reset into normal or secured expanded mode, some pins

are controlled by the External Interface Module (EIM) and are not available for general purpose functions.

In order to improve software performance, all pins can be controlled either in a port-wise or bit-wise

manner in general purpose I/O mode. Registers are provided which allow each pin to be independently

controlled by writing to a separate register. Mirror registers are also available to simplify read and write

operations by accessing all pins in a port at one time.

4.7

Analog-to-Digital Converters (ATD)

The Analog-to-Digital Converter (ATD) Module is a 16-channel, multiplexed input, successive

approximation analog-to-digital converter with a programmable resolution of 8 or 10 bits. MAC7100

devices implement one or two Analog to Digital (ATD) Converter modules; refer to Table 1 for the ATD

configuration of a specific device.

The ATD modules may be serviced by the eDMA in order to improve overall system performance. Two

DMA request channels may be used by each of the ATDs (on devices with two ATDs): one channel per

ATD to move conversion command words to the ATD command registers, and one channel per ATD to

move conversion results out of the ATD result registers.The conversion command word is used to define

parameters such as the mode of conversion, the channel to be converted and the length of the conversion.

By defining a number of conversion words in the MCUs system memory, it is possible to build a

predefined sequence of conversions which will be executed without the intervention of the CPU. It is also

possible for the CPU to write the conversion command word and to read the conversion results directly

without the need to use the eDMA.

MAC7100 ATD modules include the ability to trigger a conversion sequence based on either an external

signal or by one of two internal signals, SYSTRG0 or SYSTRG1. In order to use an external trigger source

to initiate a conversion, any one of the analog channels can be used as an off-chip trigger. The internal

trigger signal lines are connected to the Programmable Interrupt Timer (PIT), which provides two

dedicated programmable 24-bit timers to trigger the ATD. The counter associated with the SYSTRGn

signals can be programmed with the desired conversion trigger periods. This counter will count down from

the preloaded value to zero at the rate defined by the system clock frequency. When the counter reaches

zero the trigger signal is asserted to the ATD, then it is reloaded and the count down continues. For those

devices that implement two ATD modules, when it is necessary to perform synchronous conversion by

both, ATD_A and ATD_B can use the same external source, with one channel from each module assigned

as the input for this trigger. Alternatively, both modules can use the same internal system trigger.