Frequency Synthesizer; Outline; Related Registers - Renesas M16C Series User Manual

M30240 Group

3.1 Frequency Synthesizer

This section explains how to setup the frequency synthesizer for USB operation.

3.1.1 Outline

The frequency synthesizer generates the 48MHz clock that is necessary for the USB block and the f
clock. These clocks are a multiple of the external input standard clock f(X
frequency synthesizer circuit block diagram.
f(Xin)
Prescaler
03DE
16
Figure 3.1: Frequency Synthesizer Circuit Block Diagram

3.1.2 Related Registers

Table 3.1 shows a memory location diagram for the frequency synthesizer related registers; Figures 3.3
and 3.4 show the composition of the frequency synthesizer related registers.
Table 3.1: Frequency Synthesizer-Related Registers Memory Locations
Address
000A
03DB
03DC
03DD
03DE
03DF
Rev.1.00 Sep 24, 2003 Page 288 of 360
Frequency
f
PIN
Multiplier
FSP FSM
03DC
03DD
16
Register Name
Protect Register
16
Frequency Synthesizer Clock Control Register
16
Frequency Synthesizer Control Register
16
Frequency Synthesizer Multiply Register
16
Frequency Synthesizer Pre-Scaler Register
16
Frequency Synthesizer Division Register
16
f
USB
EN
USBC5
f
SYN
f
Frequency
VCO
Divider
LS
8 Bit
FSC FSD
03DF 03DB
16 16
Data Bus
PRCR
FSCCR
FSC
FSM
FSP
FSD
Frequency Synthesizer
SYN
). Figure 3.1 shows the
IN
FSCCR0
FSCCR
16
Acronym