
1996 Nov 29
22
Philips Semiconductors
Product specification
8-bit microcontrollers with OSD and VST
84C44X; 84C64X; 84C84X
12.6.1
D
ERIVATIVE REGISTER
OSDCA
Table 11
Derivative register OSDCA (address 40H)
Table 12
Description of OSCDA bits
7
6
5
4
3
2
1
0
CC34
CC24
CC14
RBLK
ROUND
STBY
VLVL
HLVL
BIT SYMBOL
DESCRIPTION
7
6
5
4
CC34
CC24
CC14
RBLK
Character colour code bits.
These bits are used for colour selection purposes. See Table 24.
Raster blanking control
(see Fig.24). When the RBLK bit is:
Logic 1, the VOB output is driven HIGH to display the OSD characters on a blank screen.
Logic 0, the VOB output returns to its normal output state on the trailing edge of VSYNCN.
Character rounding control
(see Figs 22 and 23). The rounding function generates half dots where
the corners of two dots meet. The rounding function also works with multiple cell characters.
When the ROUND bit is:
Logic 1, the rounding function is enabled.
Logic 0, the rounding function is disabled.
Stand-by.
This bit is used to enable or disable the OSD facility. When the STBY bit is:
Logic 1, the OSD oscillator is disabled.
Logic 0, the OSD oscillator is enabled and the OSD facility is available.
Vertical synchronous signal level
(see Fig.21).
This bit selects the active level of the VSYNCN input signal. When the VLVL bit is:
Logic 1, VSYNCN is active HIGH.
Logic 0, VSYNCN is active LOW.
Horizontal synchronous signal level
(see Fig.21).
This bit selects the active level of the HSYNCN input signal. When the HLVL bit is:
Logic 1, HSYNCN is active HIGH.
Logic 0, HSYNCN is active LOW.
3
ROUND
2
STBY
1
VLVL
0
HLVL
Fig.21 VSYNCN and HSYNCN active level.
handbook, full pagewidth
(VSYNCN)
HSYNCN
(HLVL = VLVL = 0)
(HLVL = VLVL = 1)
characters can be displayed
(VSYNCN)
HSYNCN
MCD180