NXP Semiconductors
FXTH87E
FXTH87E, Family of Tire Pressure Monitor Sensors
BUSCLK
DX
CLOCK SOURCE
SELECT
OFF, BUS, XCLK, EXT
PRESCALE AND SELECT
DIVIDE BY
1, 2, 4, 8, 16, 32, 64, or 128
SYNC
MAIN 16-BIT COUNTER
16-BIT COMPARATOR
INTERRUPT
LOGIC
COUNTER RESET
CHANNEL 0
PORT
LOGIC
16-BIT COMPARATOR
INTERRUPT
LOGIC
16-BIT LATCH
CHANNEL 1
PORT
LOGIC
16-BIT COMPARATOR
INTERRUPT
LOGIC
16-BIT LATCH
aaa-028012
Figure 18.ꢀTPM1 block diagram
The central component of the TPM1 is the 16-bit counter that can operate as a free-
running counter, a modulo counter, or an up- /down-counter when the TPM1 is
configured for center-aligned PWM. The TPM1 counter (when operating in normal
up-counting mode) provides the timing reference for the input capture, output
compare, and edge-aligned PWM functions. The timer counter modulo registers,
TPMMODH:TPMMODL, control the modulo value of the counter. (The values 0x0000
or 0xFFFF effectively make the counter free running.) Software can read the counter
value at any time without affecting the counting sequence. Any write to either byte of the
TPMCNT counter resets the counter regardless of the data value written.
All TPM1 channels are programmable independently as input capture, output compare,
or buffered edge-aligned PWM channels.
11.3 External signal description
When any pin associated with the timer is configured as a timer input, a passive pullup
can be enabled. After reset, the TPM1 modules are disabled and all pins default to
general-purpose inputs with the passive pullups disabled.
Each TPM1 channel is associated with an I/O pin on the MCU. The function of this pin
depends on the configuration of the channel. In some cases, no pin function is needed
so the pin reverts to being controlled by general-purpose I/O controls. When a timer has
control of a port pin, the port data and data direction registers do not affect the related
pin(s). See the Section 4 "Pinning information" for additional information about shared pin
functions.
FXTH87ERM
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© NXP B.V. 2019. All rights reserved.
Reference manual
Rev. 5.0 — 4 February 2019
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