S12 Clock, Reset and Power Management Unit (S12CPMU_UHV_V8)
MC9S12VRP Family Reference Manual Rev. 1.3
166
NXP Semiconductors
4.6.1.5
HTI - High Temperature Interrupt
In FPM the junction temperature T
J
is monitored. Whenever T
J
exceeds level T
HTIA
the status bit HTDS
is set to 1. Vice versa, HTDS is reset to 0 when T
J
get below level T
HTID
. An interrupt, indicated by flag
HTIF = 1, is triggered by any change of the status bit HTDS, if interrupt enable bit HTIE = 1.
4.6.1.6
Autonomous Periodical Interrupt (API)
The API sub-block can generate periodical interrupts independent of the clock source of the MCU. To
enable the timer, the bit APIFE needs to be set.
The API timer is either clocked by the Autonomous Clock (ACLK - trimmable internal RC oscillator) or
the Bus Clock. Timer operation will freeze when MCU clock source is selected and Bus Clock is turned
off. The clock source can be selected with bit APICLK. APICLK can only be written when APIFE is not
set.
The APIR[15:0] bits determine the interrupt period. APIR[15:0] can only be written when APIFE is
cleared. As soon as APIFE is set, the timer starts running for the period selected by APIR[15:0] bits. When
the configured time has elapsed, the flag APIF is set. An interrupt, indicated by flag APIF = 1, is triggered
if interrupt enable bit APIE = 1. The timer is re-started automatically again after it has set APIF.
The procedure to change APICLK or APIR[15:0] is first to clear APIFE, then write to APICLK or
APIR[15:0], and afterwards set APIFE.
The API Trimming bits ACLKTR[5:0] must be set so the minimum period equals 0.2 ms if stable
frequency is desired.
for the trimming effect of ACLKTR.
NOTE
The first period after enabling the counter by APIFE might be reduced by
API start up delay t
sdel
.
It is possible to generate with the API a waveform at the external pin API_EXTCLK by setting APIFE and
enabling the external access with setting APIEA.
4.7
Initialization/Application Information
4.7.1
General Initialization information
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
.
By doing a “controlled” write access in MCU Normal Mode (with the
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
.
In case of a program sequencing issue (code
runaway) the COP configuration can not be accidentally modified anymore
.
Summary of Contents for MC9S12VRP64
Page 16: ...MC9S12VRP Family Reference Manual Rev 1 3 16 NXP Semiconductors ...
Page 46: ...Device Overview S12VRP Series MC9S12VRP Family Reference Manual Rev 1 3 46 NXP Semiconductors ...
Page 236: ...S12S Debug Module S12DBGV2 MC9S12VRP Family Reference Manual Rev 1 3 236 NXP Semiconductors ...
Page 244: ...Interrupt Module S12SINTV1 MC9S12VRP Family Reference Manual Rev 1 3 244 NXP Semiconductors ...
Page 358: ...Timer Module TIM16B2CV3 MC9S12VRP Family Reference Manual Rev 1 3 358 NXP Semiconductors ...
Page 436: ...Supply Voltage Sensor BATSV2 MC9S12VRP Family Reference Manual Rev 1 3 436 NXP Semiconductors ...
Page 528: ...NVM Electrical Parameters MC9S12VRP Family Reference Manual Rev 1 3 528 NXP Semiconductors ...
Page 530: ...Package Information MC9S12VRP Family Reference Manual Rev 1 3 530 NXP Semiconductors ...
Page 531: ...Package Information MC9S12VRP Family Reference Manual Rev 1 3 NXP Semiconductors 531 ...
Page 532: ...Package Information MC9S12VRP Family Reference Manual Rev 1 3 532 NXP Semiconductors ...