STV9427 Datasheet, PDF (9/20 Pages) STMicroelectronics – HIGH SPEED MULTISYNCH ON-SCREEN DISPLAY FOR MONITOR

STV9427 - STV9428 - STV9429
FUNCTIONAL DESCRIPTION (continued)
CHARACTERS HEIGHT (Reset Value : 24h)
3FF3 - - CH5 CH4 CH3 CH2 CH1 CH0
CH[5:0] : HEIGHT of the character strips in scan lines. For
each scan line, the number of the slice which is
displayed is given by :
SLICE-NUMBER =
round
SCAN−LINE−NUMBER


CH[5:0]
x
18 _.

SCAN-LINE-NUMBER = Number of the current
scan line of the strip.
DISPLAY CONTROL (Reset Value : 00h)
3FF4 OSD FBK FL1 FL0 P9 P8 P7 P6
OSD : ON/OFF (if 0, R, G, B and FBLK outputs are 0).
FBK : Fast blanking control :
= 1, forces FBLK pin at "1" outside and inside the
OSD area. This leads to blank video RGB and
to only display OSD RGB.
= 0, FBLK pin is driven according character code
for normal display of OSD data.
FL[1:0] : Flashing mode :
- 00 : No flashing.
The character attribute is ignored,
- 01 : Flashing at fF (50% duty cycle),
- 10 : Flashing at 2 fF,
- 11 : Flashing at 4 fF.
Note : f_F is 128 time vertical frequency.
P[9:6] : Address of the 1^st descriptor of the current
displayed pages.
P[13:10] and P[5:0] = 0 ; up to 16 different pages
can be stored in the RAM.
LOCKING CONDITION TIME CONSTANT
(Reset Value : 01h)
3FF5 FR AS2 AS1 AS0 LUK BS2 BS1 BS0
FR : Free Running ; if = 1 PLL is disabled and the pixel
frequency keeps its last value.
AS[2:0] : Phase constant during locking conditions.
BS[2:0] : Frequency constant during locking conditions.
LUK : Lock unlock status bit
0 = unlocked PLL
1 = Locked PLL
CAPTURE PROCESS TIME CONSTANT
(Reset Value : 24h)
3FF6 LEN AF2 AF1 AF0 - BF2 BF1 BF0
LEN : Lock enable
0 = R,G,B, FBLK are always enabled,
1 = R,G,B, FBLK are enabled only when PLL is
locked.
AF[2:0] : Phase constant during the capture process.
BF[2:0] : Frequency constant during the capture process.
INITIAL PIXEL PERIOD (Reset Value : 28h)
3FF7 PP7 PP6 PP5 PP4 PP3 PP2 PP1 PP0
PP[7:0] : Value to initialize the pixel period of the PLL.
FREQUENCY MULTIPLIER (Reset Value : 0Ah)
3FF8 - - - - FM3 FM2 FM1 FM0
FM[3:0] : Frequency multiplier of the crystal frequency to
reach the high frequency used by the PLL to
derive the pixel frequency.
Note : For high pixel frequency (over 70MHz), write at address 3FFF,
Data F0h.
II - Descriptors
SPACING
MSB 0 L/C - - - - - -
LSB SL7 SL6 SL5 SL4 SL3 SL2 SL1 SL0
L/C : LINE or CHARACTER spacing :
= 0, spacing descriptor defined as character
height (SL[7:0] = 1 to 255 character).
= 1, spacing descriptor defined as scan line
height (SL[7:0] = 1 to 255 scan lines).
SL[7:0] : Number of selected height (character or scan
lines according L/C).
CHARACTER
MSB 1 DE CLU3 CLU2 CLU1 CLU0 C9 C8
LSB C7 C6 C5 C4 C3 C2 C1 UEN
DE
: Display enable :
= 0, R = G = B = 0 and FBLK = FBK bit of display
control register on the whole strip,
= 1, display of the characters.
CLU[3:0] : Active color selection at the begining of the
strip.
C[9:1] : Address of the first character code of the strip.
UEN : UDC enable
0 : codes 240 to 254 (FOh to FEh) are read in
ROM,
1 : codes 240 to 255 (FOh to FFh) are read in
RAM (UDC).
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