LFEBS12UB Freescale Semiconductor, LFEBS12UB Datasheet - Page 578

• Manufacturer Part Number: LFEBS12UB
• Description: KIT STUDENT LEARNING S12 DG128
• Manufacturer: Freescale Semiconductor

Specifications of LFEBS12UB

• Architecture: 8/16-bit
• Code Gen Tools Included: Code Warrior
• Silicon Manufacturer: Freescale
• Core Architecture: S12
• Core Sub-architecture: S12
• Silicon Core Number: MC9S12
• Silicon Family Name: S12D
• Kit Contents: HCS12 DG128 Learning Kit
• Rohs Compliant: Yes
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

Chapter 14 Enhanced Capture Timer (ECT16B8CV3)
14.4.1.4
The modulus down-counter can be used as a time base to generate a periodic interrupt. It can also be used
to latch the values of the IC registers and the pulse accumulators to their holding registers.
The action of latching can be programmed to be periodic or only once.
14.4.1.5
By enabling the PRNT bit of the TSCR1 register, the performance of the timer can be enhanced. In this
case, it is possible to set additional prescaler settings for the main timer counter and modulus down counter
and enhance delay counter settings compared to the settings in the present ECT timer.
14.4.1.6
The flags in the ECT can be cleared one of two ways:
578
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1. Normal flag clearing mechanism (TFFCA = 0)
2. Fast flag clearing mechanism (TFFCA = 1)
At the same time the pulse accumulator is cleared.
Any of the ECT flags can be cleared by writing a one to the flag.
With the timer fast flag clear all (TFFCA) enabled, the ECT flags can only be cleared by accessing
the various registers associated with the ECT modes of operation as described below. The flags
cannot be cleared via the normal flag clearing mechanism. This fast flag clearing mechanism has
the advantage of eliminating the software overhead required by a separate clear sequence. Extra
care must be taken to avoid accidental flag clearing due to unintended accesses.
— Input capture
— Output compare
— Timer counter
— Pulse accumulator A
— Pulse accumulator B
— Modulus down counter
A read from an input capture channel register causes the corresponding channel flag, CxF, to
be cleared in the TFLG1 register.
A write to the output compare channel register causes the corresponding channel flag, CxF, to
be cleared in the TFLG1 register.
Any access to the TCNT register clears the TOF flag in the TFLG2 register.
Any access to the PACN3 and PACN2 registers clears the PAOVF and PAIF flags in the
PAFLG register.
Any access to the PACN1 and PACN0 registers clears the PBOVF flag in the PBFLG register.
Any access to the MCCNT register clears the MCZF flag in the MCFLG register.
Modulus Down-Counter
Precision Timer
Flag Clearing Mechanisms
MC9S12XE-Family Reference Manual Rev. 1.23
Freescale Semiconductor