Bit
Bit name
Function
9 to 8
BUSDIV[1:0]
Divider for the main system clock HCLK
00
B
f
HCLK
= f
PLLCLKOUT
01
B
f
HCLK
= f
PLLCLKOUT
/ 2
10
B
f
HCLK
= f
PLLCLKOUT
/ 3
11
B
f
HCLK
= f
PLLCLKOUT
/ 4
5 to 0
VO0DIV[5:0]
Divider for Video Output clock VO0CLK
0
f
VO0CLK
= f
PLLCLKOUT
/ 2
1
2
f
VO0CLK
= f
PLLCLKOUT
/ 3
...
...
62
f
VO0CLK
= f
PLLCLKOUT
/ 63
63
f
VO0CLK
= f
PLLCLKOUT
/ 64
Caution
If SYSCLKCTRL.BUSDIV is changed, a software reset by
SYSRESET.SWRESET = 1 must be issued.
Reset values
Below tables defines the initial values of the SYSCLKCTRL register for Ravin-L
and Ravin-M.
Table 4-8 Ravin-L SYSCLKCTRL reset values
MODE9
(IRAMCLKEN)
MODE7
(SDREN)
MODE4
(dividers)
Reset value
0
0
0
003F 0317
H
0
0
1
003F 032F
H
0
1
0
803F 0317
H
0
1
1
803F 032F
H
1
0
0
403F 0317
H
1
0
1
403F 032F
H
1
1
0
C03F 0317
H
1
1
1
C03F 032F
H
Table 4-9 Ravin-M SYSCLKCTRL reset values
MODE7
(SDREN)
MODE4
(dividers)
Reset value
0
0
0017 0105
H
0
1
0017 0104
H
1
0
8017 0105
H
1
1
8017 0104
H
SDREN default
The SDREN default value is subject to the boot mode function and takes on the
level of MODE7 at RESET release:
•
MODE7 = 0 SDREN = 0: SDRAM disabled after RESET
•
MODE7 = 1 SDREN = 1: SDRAM enabled after RESET
System Controller
Chapter 4
Preliminary User's Manual S19203EE1V3UM00
105
Содержание uPD72257
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