6 CLOCK MANAGEMENT UNIT (CMU)
6-24
Seiko Epson Corporation
S1C33L26 TECHNICAL MANUAL
PLL Control Register 0 (CMU_PLLCTL0)
Register name Address
Bit
Name
Function
Setting
Init. R/W
Remarks
PLL Control
Register 0
(CMU_
PLLCTL0)
0x300108
(8 bits)
D7–4 PLLN[3:0]
PLL multiplication rate setup
PLLN[3:0] Multiplication rate 0x0 R/W Write-protected
0xf
0xe
0xd
0xc
0xb
0xa
0x9
0x8
0x7
0x6
0x5
0x4
0x3
0x2
0x1
0x0
x16
x15
x14
x13
x12
x11
x10
x9
x8
x7
x6
x5
x4
x3
x2
x1
D3–2 PLLV[1:0]
PLL V-divider setup
PLLV[1:0]
W
0x1 R/W
0x3
0x2
0x1
0x0
8
4
2
Not allowed
D1
–
reserved
–
–
–
0 when being read.
D0
PLLPOWR PLL enable
1 Enable
0 Disable
0
R/W Write-protected
Note: Make sure that the PLL is turned off (PLLPOWR = 0) before altering D[7:4] in this register.
D[7:4]
PLLN[3:0]: PLL Multiplication Rate Setup Bits
Sets the frequency multiplication rate of the PLL.
10.8 PLL Frequency Multiplication Rates
Table 6.
PLLN[3:0]
Multiplication rate
0xf
x16
0xe
x15
0xd
x14
0xc
x13
0xb
x12
0xa
x11
0x9
x10
0x8
x9
0x7
x8
0x6
x7
0x5
x6
0x4
x5
0x3
x4
0x2
x3
0x1
x2
0x0
x1
(Default: 0x0)
PLL output clock frequency = PLL input clock frequency
×
multiplication rate
Note: The frequency multiplication rate must be set so that the PLL output clock frequency does not
exceed the upper-limit operating clock frequency. For the multiplication rates that can be set
and the range of the output clock frequency, see “Electrical Characteristics.”
D[3:2]
PLLV[1:0]: PLL V-Divider Setup Bits
Sets the W value so that the f
VCO
frequency obtained by <Output clock frequency
×
W> falls within the
range of 100 to 400 MHz.