LH79524/LH79525 User’s Guide
Reset, Clock, and Power Controller
Version 1.0
13-17
13.2.2.7 System Clock Prescaler Register (SYSCLKPRE)
HCLK is the System Clock. This register allows a divisor to be programmed that is used to
divide the system PLL frequency to derive HCLK. The prescaled HCLK frequency is
defined by:
Following reset, the prescaler is programmed to divide by 30. Table 13-18 shows example
values for HDIV.
Table 13-16. SYSCLKPRE Register
BIT
31
30
29
28
27
26
25
24
23
22
21
20
19
18
17
16
FIELD
///
RESET
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
RW
RO
RO
RO
RO
RO
RO
RO
RO
RO
RO
RO
RO
RO
RO
RO
RO
BIT
15
14
13
12
11
10
9
8
7
6
5
4
3
2
1
0
FIELD
///
HDIV
RESET
0
0
0
0
0
0
0
0
0
0
0
0
1
1
1
1
RW
RO
RO
RO
RO
RO
RO
RO
RO
RO
RO
RO
RO
RW
RW
RW
RW
ADDR
0xFF 0x18
Table 13-17. SYSCLKPRE Fields
BITS
NAME
DESCRIPTION
31:4
///
Reserved
Reading returns 0. Write the reset value.
3:0
HDIV
HCLK Divisor
Program with the divisor for the HCLK prescaler. All
HDIV combinations are valid except 0b0000.
Table 13-18. SYSCLKPRE Register Values
HDIV
DIVISOR
ƒ(HCLK)
0b0000
—
Invalid
0b0001
2
ƒ(System PLL)/2
0b0010
4
ƒ(System PLL)/4
0b0011
6
ƒ(System PLL)/6
0b0100
8
ƒ(System PLL)/8
0b0101
10
ƒ(System PLL)/10
:
:
:
0b1111 (default)
30
ƒ(System PLL)/30
ƒ(HCLK)
ƒ
ƒ(SystemPLL)
2
HDIV
×
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