Chapter 14 8/16-Bit Ppg; Outline - Fujitsu F2MC-16LX MB90580 Series Hardware Manual

Chapter 14:
8/16-Bit PPG

14.1 Outline

The 8/16-bit PPG timer is an 8-bit reload timer module, and outputs PPG by control pulse output according
to timer operation.
The hardware includes two eight-bit down counters, four eight-bit reload registers, one 16-bit control
register, two external pulse output pins, and two interrupt outputs. The following functions are
implemented:
• 8-bit PPG output 2-CH independent operation mode
This is a mode for operating independent 2-CH 8-bit PPG timer, in which PPG0 and PPG1 pins corre-
spond to outputs from PPG0 and PPG1 respectively.
• 16-bit PPG output operation mode
In this mode, PPG0 and PPG1 are combined to be operated as a 1-CH 8/16-bit PPG timer operating as
a 16-bit timer. Because PRG0 and PRG1 outputs are reversed by an underflow from PRG1 outputting
the same output pulses from PRG0 and PRG1 pins.
• 8 + 8 bit PPG output operation mode
In this mode, PPG0 is operated as an 8-bit pre-scaler, in which an underflow output of PPG0 is used as
a clock source for PPG1. A toggle output of PPG0 and PPG output of PPG1 are output from PPG0 and
PPG1 respectively.
• PPG output operation
The 8/16-bit PPG timer can output pulse waveforms with variable period and duty ratio. Also, it can be
used as D/A converter in conjunction with an external circuit.