mcf52221 Freescale Semiconductor, Inc, mcf52221 Datasheet - Page 11

• Manufacturer Part Number: mcf52221
• Description: Mcf52223 Coldfire Microcontroller 32-bits Microcontrollers With Usb And Zigbee
• Manufacturer: Freescale Semiconductor, Inc

generate output waveforms and timer software delays. The 16-bit pulse accumulator can operate as a simple event counter or a
gated time accumulator.
1.2.14
The two periodic interrupt timers (PIT0 and PIT1) are 16-bit timers that provide interrupts at regular intervals with minimal
processor intervention. Each timer can count down from the value written in its PIT modulus register or it can be a free-running
down-counter.
1.2.15
The Real-Time Clock (RTC) module maintains the system (time-of-day) clock and provides stopwatch, alarm, and interrupt
functions. It includes full clock features: seconds, minutes, hours, days and supports a host of time-of-day interrupt functions
along with an alarm interrupt.
1.2.16
The MCF52223 has an 8-channel, 8-bit PWM timer. Each channel has a programmable period and duty cycle as well as a
dedicated counter. Each of the modulators can create independent continuous waveforms with software-selectable duty rates
from 0% to 100%. The PWM outputs have programmable polarity, and can be programmed as left aligned outputs or center
aligned outputs. For higher period and duty cycle resolution, each pair of adjacent channels ([7:6], [5:4], [3:2], and [1:0]) can
be concatenated to form a single 16-bit channel. The module can, therefore, be configured to support 8/0, 6/1, 4/2, 2/3, or 0/4
8-/16-bit channels.
1.2.17
The watchdog timer is a 32-bit timer that facilitates recovery from runaway code. The watchdog counter is a free-running
down-counter that generates a reset on underflow. To prevent a reset, software must periodically restart the countdown.
1.2.18
The clock module contains a crystal oscillator, 8 MHz on-chip relaxation oscillator (OCO), phase-locked loop (PLL), reduced
frequency divider (RFD), low-power divider status/control registers, and control logic. To improve noise immunity, the PLL,
crystal oscillator, and relaxation oscillator have their own power supply inputs: VDDPLL and VSSPLL. All other circuits are
powered by the normal supply pins, VDD and VSS.
1.2.19
The MCF52223 has a single interrupt controller that supports up to 63 interrupt sources. There are 56 programmable sources,
49 of which are assigned to unique peripheral interrupt requests. The remaining seven sources are unassigned and may be used
for software interrupt requests.
1.2.20
The direct memory access (DMA) controller provides an efficient way to move blocks of data with minimal processor
intervention. It has four channels that allow byte, word, longword, or 16-byte burst line transfers. These transfers are triggered
by software explicitly setting a DCRn[START] bit or by the occurrence of certain UART or DMA timer events.
Freescale Semiconductor
Periodic Interrupt Timers (PIT0 and PIT1)
Real-Time Clock (RTC)
Pulse-Width Modulation (PWM) Timers
Software Watchdog Timer
Phase-Locked Loop (PLL)
Interrupt Controller (INTC)
DMA Controller
MCF52223 ColdFire Microcontroller, Rev. 2
MCF52223 Family Configurations
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