Samsung S3C2440A User Manual
Page 228
S3C2440A RISC MICROPROCESSOR
CLOCK & POWER MANAGEMENT
7
-21
PLL CONTROL REGISTER (MPLLCON & UPLLCON)
Register Address R/W
Description
Reset
Value
MPLLCON
0x4C000004
R/W
MPLL configuration register
0x00096030
UPLLCON
0x4C000008
R/W
UPLL configuration register
0x0004d030
PLLCON Bit
Description
Initial
State
MDIV
[19:12]
Main divider control
0x96 / 0x4d
PDIV
[9:4]
Pre-divider control
0x03 / 0x03
SDIV
[1:0]
Post divider control
0x0 / 0x0
NOTE
When you set MPLL&UPLL values, you have to set the UPLL value first and then the MPLL value. (Needs intervals
approximately 7 NOP)
PLL VALUE SELECTION TABLE
It is not easy to find a proper PLL value. So, we recommend referring to the following PLL value recommendation
table.
Input Frequency
Output Frequency
MDIV
PDIV
SDIV
12.0000MHz
48.00 MHz
(Note)
56(0X38) 2 2
12.0000MHz
96.00 MHz
(Note)
56(0x38) 2 1
12.0000MHz
271.50 MHz
173(0xad)
2
2
12.0000MHz
304.00 MHz
68(0x44)
1
1
12.0000MHz
405.00 MHz
127(0x7f)
2
1
12.0000MHz
532.00 MHz
125(0x7d)
1
1
16.9344MHz
47.98 MHz
(Note)
60(0x3c) 4 2
16.9344MHz
95.96 MHz
(Note)
60(0x3c) 4 1
16.9344MHz
266.72
MHZ
118(0x76) 2
2
16.9344MHz
296.35
MHZ
97(0x61) 1
2
16.9344MHz 399.65
MHz 110(0x6e) 3 1
16.9344MHz 530.61
MHz
86(0x56) 1 1
16.9344MHz 533.43
MHz 118(0x76) 1 1
NOTE
The 48.00MHz and 96MHz output is used for UPLLCON register.