M30240ECFP MITSUBISHI [Mitsubishi Electric Semiconductor], M30240ECFP Datasheet - Page 42

• Manufacturer Part Number: M30240ECFP
• Description: M30240 Group Specification
• Manufacturer: MITSUBISHI [Mitsubishi Electric Semiconductor]

Specifications in this manual are tentative and subject to change
Frequency Synthesizer Circuit
Figure 1.25: Frequency Synthesizer Multiply Register (FSM)
Figure 1.26: Frequency Synthesizer Divide Register (FSD)
2.17.2 Multiplier
2.17.3 Divider
Clock f
and the clock input to the multiplier (f
• f
Clock f
and the clock input to the divider (f
• f
Setting FSM to 255 disables the multiplier and f
Setting FSD to 255 disables the divider and f
VCO
SYN
Note 1: n must be chosen such that f
Note 2: Minimum f
MSB
7
MSB
= f
VCO
= f
SYN
7
VCO
PIN
is a divided down version of clock f
is a multiplied up version of clock f
Bit 7
Bit 7
x 2( n +1) where n is the decimal equivalent of the value loaded in FSM.
/ 2(m+1) where m is the decimal equivalent of the value loaded in FSD.
PIN
Bit 6
f
48.00 MHz 1
48.00 MHz 127
Bit 6
VCO
f
1 MHz
2 MHz
4 MHz
6 MHz
12 MHz
PIN
is 1 MHz.
Bit 5
Bit 5
f
VCO
FSD
Dec(m)
f
PIN
FSM
Dec(n)
33
11
5
3
1
VCO
/2(m+1) = f
VCO
x 2(n+1) = f
Bit 4
PIN
Bit 4
) from the multiplier is as follows:
) from the prescaler is as follows:
equals 48 MHz.
Hex(m)
01
7F
SYN
Hex(n)
4A
0B
05
03
01
1-42
Bit 3
SINGLE-CHIP 16-BIT CMOS MICROCOMPUTER
Bit 3
VCO
VCO
SYN
PIN
VCO
(See Figure 1.25). The relationship between f
= f
(See Figure 1.26). The relationship between f
f
12.00 MHz
187.50 KHz
SYN
Bit 2
f
48.00 MHz
48.00 MHz
48.00 MHz
48.00 MHz
48.00 MHz
VCO
= f
Bit 2
VCO
PIN
.
.
Bit 1
Bit 1
Bit 0
Bit 0
Mitsubishi microcomputers
M30240 Group
LSB
0
LSB
0
Address: 03DF
Access: R/W
Reset:
Address: 03DD
Access: R/W
Reset:
FF
FF
16
16
16
16
VCO
SYN