MC9S12G FREESCALE [Freescale Semiconductor, Inc], MC9S12G Datasheet - Page 374

• Manufacturer Part Number: MC9S12G
• Description: Ignores external trigger. Performs one conversion sequence and stops.
• Manufacturer: FREESCALE [Freescale Semiconductor, Inc]

S12 Clock, Reset and Power Management Unit (S12CPMU)
10.7
10.7.1
Usually applications run in MCU Normal Mode
It is recommended to write the CPMUCOP register in any case from the application program initialization
routine after reset no matter if the COP is used in the application or not, even if a configuration is loaded
via the flash memory after reset
right value for the application) the write once for the COP configuration bits (WCOP,CR[2:0]) takes place
which protects these bits from further accidental change
runaway) the COP configuration can not be accidentally modified anymore
10.7.2
In many applications the COP is used to check that the program is running and sequencing properly
the COP is kept running during Stop Mode and periodic wake-up events are needed to service the COP on
time and maybe to check the system status
For such an application it is recommended to use the ACLK as clock source for both COP and API
guarantees lowest possible IDD current during Stop Mode
using the same clock source for both, COP and API
The Interrupt Service Routine (ISR) of the Autonomous Periodic Interrupt API should contain the write
instruction to the CPMUARMCOP register
(alternating sequence of $55 and $AA) of the application software
Using this method, then in the case of a runtime or program sequencing issue the application “main
routine” is not executed properly anymore and the alternating values are not provided properly
COP is written at the correct time (due to independent API interrupt request) but the wrong value is written
(alternating sequence of $55 and $AA is no longer maintained) which causes a COP reset
374
This document is valid for the S12G96 and the S12G128 device. All information related to other devices is preliminary.
Initialization/Application Information
General Initialization information
Application information for COP and API usage
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By doing a “controlled” write access in MCU Normal Mode (with the
MC9S12G Family Reference Manual,
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The value (byte) written is derived from the “main routine”
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In case of a program sequencing issue (code
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Additionally it eases software implementation
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