CLOCK & POWER MANAGEMENT S3C2440A RISC MICROPROCESSOR
7-20
CLOCK GENERATOR & POWER MANAGEMENT SPECIAL REGISTER

LOCK TIME COUNT REGISTER (LOCKTIME)

Register Address R/W Description Reset Value

LOCKTIME 0x4C000000 R/W PLL lock time count register 0xFFFFFFFF

LOCKTIME Bit Descriptio n Initial Stat e

U_LTIME [31:16] UPLL lock time count value for UCLK.
(U_LTIME 300uS)
0xFFFF
M_LTIME [15:0] MPLL lock tim e count value for FCLK, HCLK, and PCLK
(M_LTIME 300uS)
0xFFFF

MPLL Control Register

Mpll = (2 * m * Fin) / (p * 2s)
m = (MDIV + 8), p = (PDIV + 2), s = SDIV

UPLL Control Register

Upll = (m * Fin) / (p * 2s)
m = (MDIV + 8), p = (PDIV + 2), s = SDIV

PLL Value Selection Guide (MPLLCON)

1. Fout = 2 * m * Fin / ( p*2s), Fvco = 2 * m * Fin / p where : m=MDIV+8, p=PDIV+2, s=SDIV
2. 600MHz FVCO 1.2GHz
3. 200MHz FCLKOUT 600MHz
4. Don't set the P or M value as zero, that is, setting the P=000000, M=00000000 can cause malfunction of
the PLL.
5. The proper range of P and M: 1 P 62, 1 M 248
NOTE
Although there is the rule for choosing PLL value, we recommend only the values in the PLL value recommendation
table. If you have to use another value, please contact us.