MC9S08RC8 Datasheet, PDF (131/234 Pages) Freescale Semiconductor, Inc – Microcontrollers

Timer/PWM (TPM) Block Description
10.3 TPM Block Diagram
The TPM uses one input/output (I/O) pin per channel, TPM1CHn where n is the channel number (for
example, 0–4). The TPM shares its I/O pins with general-purpose I/O port pins (refer to the Pins and
Connections chapter for more information). Figure 10-2 shows the structure of a TPM. Some MCUs
include more than one TPM, with various numbers of channels.
BUSCLK
XCLK
TPM1) EXT CLK
SYNC
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MAIN 16-BIT COUNTER
16-BIT COMPARATOR
TPM1MODH:TPM1
CHANNEL 0
16-BIT COMPARATOR
TPM1C0VH:TPM1C0VL
16-BIT LATCH
CHANNEL 1
16-BIT COMPARATOR
TPM1C1VH:TPM1C1VL
16-BIT LATCH
CLOCK SOURCE
SELECT
OFF, BUS, XCLK, EXT
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COUNTER RESET
PRESCALE AND SELECT
DIVIDE BY
1, 2, 4, 8, 16, 32, 64, or 128
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INTERRUPT
LOGIC
ELS0B ELS0A
CH0F
MS0B MS0A
CH0IE
ELS1B ELS1A
CH1F
MS1B MS1A
CH1IE
PORT
LOGIC
TPM1CH0
INTERRUPT
LOGIC
PORT
LOGIC
TPM1CH1
INTERRUPT
LOGIC
CHANNEL n
16-BIT COMPARATOR
TPM1CnVH:TPM1CnVL
16-BIT LATCH
ELSnB ELSnA
CHnF
MSnB MSnA
CHnIE
PORT
LOGIC
TPM1CHn
INTERRUPT
LOGIC
Figure 10-2. TPM Block Diagram
The central component of the TPM is the 16-bit counter that can operate as a free-running counter, a
modulo counter, or an up-/down-counter when the TPM is configured for center-aligned PWM. The TPM
counter (when operating in normal up-counting mode) provides the timing reference for the input capture,
MC9S08RC/RD/RE/RG Data Sheet, Rev. 1.11
Freescale Semiconductor
131