MAC7200 datasheet(931/976 Pages) FREESCALE

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Initialization/Application Information

MAC7200 Microcontroller Family Reference Manual, Rev. 2

Freescale Semiconductor

853

2. Select the desired slew rate by setting or clearing the SLEWDIS and SLEW bits in the CONFIG2

Note that, when the external bus is used to boot the device (i.e.-the System is in Expanded Mode), the

CLKOUT clock output is automatically enabled. Otherwise, the CLKOUT clock output is disabled, but

may be manually enabled via the above steps.

34.8.3.2

Disabling the CLKOUT output

To disable the CLKOUT clock on pad PD2, simply configure pad PD2 to be a General Purpose Input, as

described in Section 34.8.3.3, “Using pad PD2 as a General Purpose Input.”

34.8.3.3

Using pad PD2 as a General Purpose Input

To enable pin PD2 as a General Purpose Input (and therefore disable the CLKOUT clock), do the

following:

•

Put pin PD2 into GPIO Mode (Clear the MODE bit in the CONFIG2 register for Port D)

•

Put pin PD2 into Input Mode (Clear the DDR bit in the CONFIG2 register for Port D)

Note that, when the external bus is not used to boot the device (i.e.-the System is not in Expanded Mode),

the PD2 pin is automatically configured as a General Purpose Input.

34.8.3.4

Using pad PD2 as a General Purpose Output

It is not possible to use pad PD2 as a General Purpose Output. Pad PD2 behaves virtually identically if it

is configured as a General Purpose Output or in Peripheral Mode. In Peripheral Mode, the open drain

functionality is disabled; In GPO Mode, the open drain functionality may be enabled/disabled via the

ODER bit.

34.8.4

Unbonded Pins

All port pins (Port A, B, C, D, F, G) that are not bonded out on a particular package should be placed in

GPO mode to reduce power consumption. Otherwise the floating inputs might result in unneeded current

draw.

MAC7200 Datasheet(PDF) 931 Page - Freescale Semiconductor, Inc