Datasheet

MC56F825x/MC56F824x Digital Signal Controller, Rev. 3
General System Control Information
Freescale Semiconductor40
• Peripheral clocks for Quad Timers and SCIs with a high-speed (2x) option
• Power-saving clock gating for peripherals
• Controls for enabling/disabling functions of large regulator standby mode with write protection capability
• Allowing selected peripherals to run in stop mode to generate stop recovery interrupts
• Controls for programmable peripheral and GPIO connections
• Software chip reset
• I/O short address base location control
• Peripheral protection control to provide runaway code protection for safety-critical applications
• Controls for output of internal clock sources to CLKO pin
• Four general-purpose software control registers that are reset only at power-on
• Peripheral stop mode clocking control
5.7 Inter-Module Connections
The operations between on-chip peripherals can be synchronized or cascaded through internal module connections to support
particular applications. Examples include synchronization between ADC sampling and PWM waveform generation for a power
conversion application, and synchronization between timer pulse outputs and DAC waveform generation for a printer
application. The user can program the internal Crossbar Switch or Comparator input multiplexes to connect one on-chip
peripheral’s outputs to other peripherals’ inputs.
5.7.1 Comparator Connections
The MC56F825x/MC56F824x includes three high-speed comparators. Each comparator input has a 4-to-1 input mux, allowing
it to sample a variety of analog sources. Some of these inputs share package pins with the on-chip ADCs; see Table 5
on page 18.
Each comparator is paired with a dedicated, programmable, 5-bit on-chip voltage reference DAC (VREF_DAC). Optionally,
an on-chip 12-bit DAC can be internally fed to each comparator’s positive input 1 (CMPn_P1) or negative input 3 (CMPn_M3).
In addition, all three comparators’ positive input 3 (CMPn_P3) can be connected together to package pin CMP_REF. Other
inputs can be routed to package pins when the corresponding pin is configured for peripheral mode in the GPIO module.