PXS20RM Datasheet, PDF (1297/1368 Pages) Freescale Semiconductor, Inc – PXS20 Microcontroller

Chapter 44
Sine Wave Generator (SWG)
Sine Wave Generator (SWG)
44.1 Introduction
The Sine Wave Generator (SWG) generates a high-quality sinusoidal voltage signal. It can be programmed
with the desired oscillation frequency and amplitude voltage. A wide frequency range (1–50 kHz in 16 Hz
steps) is easily programmable through a simple register interface. The linearity/noise performances are
carefully optimized through digital processing.
Figure 44-1 shows a block diagram of the SWG.
Input clock
x phase
generator
SWG
sin(x)
generator
Digital-to-
analog
converter
Sinusoidal signal out
Figure 44-1. SWG block diagram
44.2 Features
• Input clock frequency range: 12–20 MHz
• Output sinusoidal signal:
— Frequency range: 1–50 kHz
— Peak-to-peak amplitude: 0.47–2.26 V
44.3 Memory map and register description
The memory map of the SWG is shown in Table 44-1. The address of each register is given as an offset to
the SWG base address. Registers are listed in address order, identified by complete name and mnemonic,
and list the type of accesses allowed.
Table 44-1. SWG memory map
Address offset
Register
Location
0x0
SWG control register (SWG_CTRL)
0x4
SWG status register (SWG_STAT)
on page 44-1
on page 44-3
44.3.1 SWG control register (SWG_CTRL)
This register controls the operation of the SWG.
Freescale Semiconductor
PXS20 Microcontroller Reference Manual, Rev. 1
44-1