ST92185B STMicroelectronics, ST92185B Datasheet - Page 138

• Manufacturer Part Number: ST92185B
• Description: 16k/24k/32k Rom Hcmos Mcu With On-screen-display
• Manufacturer: STMicroelectronics

ST92185B - SYNC CONTROLLER
SYNC CONTROLLER (Cont’d)
7.5.4.2 Composite Sync Input Mode
This mode is very similar to the “Standard Sync In-
put Mode” described above. It is also accessed
when both MOD1 and MOD0 bits are reset.
In Composite Sync mode, a single CSYNC/
HSYNC input pin is used to enter both the horizon-
tal and vertical sync pulses (VSEP control bit is set
to 1). In this mode, the VSYNC pin must be tied to
VSS on the application board to prevent a floating
CMOS input configuration.
Figure 84. STV2160 TXTOUT Timings
n
138/178
TXTOUT
TXTOUT
623
311
8µs
624
312
8µs
8µs
625
313
2nd TV Field
8µs
314
1
58µs
1st TV Field
58µs
6µs
8µs
315
2
38µs 8µs
The CSYNC signal characteristics are assumed to
perfectly respect the STV2160 TXTOUT pin spec-
ification which is reviewed in
85.
The vertical sync signal is extracted from the
CSYNC signal by the mean of an Up/Down coun-
ter used as a digital integrator. The counter works
in “Up” mode during the sync pulses.
Two time constants can be programmed using the
VDLY control bit (refer to the register description).
The smallest one corresponds to 16µs; the second
one being 32µs.
3
316
317
4
318
5
Figure 84
319
6
VR02092B
&
Figure