mcimx27- Freescale Semiconductor, Inc, mcimx27- Datasheet - Page 20

• Manufacturer Part Number: mcimx27-
• Description: Multimedia Applications Processor
• Manufacturer: Freescale Semiconductor, Inc

Functional Description and Application Information
The pcmcia_if host adapter module provides the control logic for PCMCIA socket interfaces, and requires
some additional external analog power switching logic and buffering. The additional external buffers
allow the pcmcia_if host adapter module to support one PCMCIA socket. The pcmcia_if shares its chip
level I/O with the external interface to memory (EIM) pins. Additional logic is required to multiplex the
EIM and the pcmcia_if on the same pins.
2.3.26
Two on-chip Digital Phase Lock Loop (DPLLs) provide clock generation in digital and mixed
analog/digital chips designed for wireless communication and other applications. The DPLLs produce a
high-frequency chip clock signals with a low frequency and phase jitter.
2.3.27
The Pulse-Width Modulator (PWM) has a 16-bit counter and is optimized to generate sounds from stored
sample audio images; it can also generate tones. The PWM uses 16-bit resolution and a 4 × 16 data FIFO
to generate sound. The 16-bit up-counter has a source selectable clock with 4 × 16 FIFO to minimize
interrupt overhead. Clock-in frequency is controlled by a 12-bit prescaler for the division of a clock.
Capable of sound and melody generation, the PWM has an active-high or active-low configurable output,
and can be programmed to be active in low-power and debug modes. The PWM can be programmed to
generate interrupts at compare and rollover events.
2.3.28
The Real Time Clock (RTC) module maintains the system clock, provides stopwatch, alarm, and
interrupt functions, and supports the following features:
The prescaler converts the incoming crystal reference clock to a 1 Hz signal, which is used to increment
the seconds, minutes, hours, and days TOD counters. The alarm functions, when enabled, generate RTC
interrupts when the TOD settings reach programmed values. The sampling timer generates
fixed-frequency interrupts, and the minute stopwatch allows for efficient interrupts on very small
boundaries.
2.3.29
The Run-Time Integrity Checker (RTIC) is one of the security components in the i.MX27/MX27L
processors. Its purpose is to ensure the integrity of the peripheral memory contents and assist with boot
authentication. The RTIC has the ability to verify the memory contents during system boot and during
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Full clock—days, hours, minutes, seconds
Minute countdown timer with interrupt
Programmable daily alarm with interrupt
Sampling timer with interrupt
Once-per-day, once-per-hour, once-per-minute, and once-per-second interrupts
Operation at 32.768 kHz or 32 kHz, or 38.4 kHz (determined by reference clock crystal)
Digital Phase Lock Loop (DPLL)
Pulse-Width Modulator (PWM)
Real Time Clock (RTC)
Run-TIme Integrity Checker (RTIC)
Preliminary—Subject to Change Without Notice
i.MX27 and i.MX27L Data Sheet, Rev. 1.2
Freescale Semiconductor