LC74950BG
No.A1647-15/37
Registers related to the control of clock
Name
Functions
Sub address
bit width
CLKININV
This register controls the inversion of CLKIN when the CLKIN input is used as a
reference clock to PLL.
0: Uses CLKIN in its original form
1: Uses CLKIN in its inverted form
0x00
2
HSINV
This register controls the inversion of HSIN input. The HSIN must be used in its
inverted form when the polarity of HSIN input is negative.
0: Original form (when HSIN is positive)
1: Inverted form (when HSIN is negative)
0x02
1
CLKINDIV
This register sets the frequency division ratio of CLKIN to an arbitrary value
(1/1 to1/64) when the CLKIN is used as a reference clock to PLL.
1/(CLKINDIV[5:0]+1) division
0x40
6
CLKSEL
This register selects the operating mode.
000: (External clock mode (PLL not used)
001: (External clock mode (PLL used)
010: H-lock PLL mode
011: Panel PLL mode <1>
100: Panel PLL mode <2>
0x00
3
CLKADCINV
This register controls the inversion of the ADC sampling clock (CLKADC).
0: Uses CLKADC in its original form
1: Uses CLKADC in its inverted form
0x00
1
CLKOUTINV
This register controls the inversion of the ADC-generated clock. (CLKOUT).
0: Uses CLKOUT in its original form
1: Uses CLKOUT in its inverted form
0x01
1
CLKOUT1INV
This register controls the inversion of CLKOUT (video clock output).
0: Original form
1: Inverted form
0x00
1
CLKOUT2INV
This register controls the inversion of CLKOUT2 (panel clock output).
0: Original form
1: Inverted form
0x00
1
*2 Clock control register (CLKSEL, 00h, bits 2-0) specifications
CLKSEL
(bit2-0)
CLKADC*3
(ADC sampling clock)
FIN
(PLL reference)
CLKOUT2
(Clock output)
Remarks
000
CLKIN/2 (13.5MHz)
L fixed (PLL not used)
CLKIN(27MHz)
External clock mode (PLL not used)
001
FOUT (PLL output)
CLKIN *4
FOUTX2
(PLL output X2)
External clock mode (PLL used)
010
FOUT (PLL output)
HSIN *5
FOUTX2
(PLL output X2)
H-lock PLL mode
011
CLKIN/2
CLKIN *4
FOUT (PLL output)
Panel PLL mode <1>
100
CLKIN
CLKIN *4
FOUT (PLL output)
Panel PLL mode <2>
*3: Register CLKADCINV (00h, bit 3) allows for clock inversion.
*4: Register CLKINDIV (40h, bits 5-0) allows for division of clock frequency (1/1 to 1/64).
*5: Register HSINV (03h, bit 3) allows for HSIN inversion.