mc68hc05bs8 Freescale Semiconductor, Inc, mc68hc05bs8 Datasheet - Page 79

• Manufacturer Part Number: mc68hc05bs8
• Description: Mc68hc05 Family Of Low-cost Single-chip Microcontrollers.
• Manufacturer: Freescale Semiconductor, Inc

9.3
The sync detector determines whether the incoming sync signal is active. Both sync high and low
pulse widths must be within the specific values to be regarded as active. The respective HDET
and/or VDET flags will be set if the HSYNC and VSYNC signals are active.
9.4
If no active sync signals are detected, a free-running sync signal generator will be enabled. It
generates a pseudo vertical sync at 63.78Hz (1/(t
57.14KHz (1/(t
at the inputs and will be fed to the VTTL and HTTL pins if the pins are selected for VTTL and HTTL
function.
If both vertical and horizontal sync signals are detected (VDET and HDET are set), the SOUT bit
must be set in order to output the processed signals.
MC68HC05BS8
Sync Detection
Free-running Pseudo Sync Signal Generator
CYC
x 35)). This set of free running sync signals replaces the inactive sync signals
Figure 9-1 Sync Signal Polarity Correction
Negative polarity pure horizontal sync signal
Positive polarity pure horizontal sync signal
SYNC SIGNAL PROCESSOR
Negative polarity composite sync signal
Positive polarity composite sync signal
CYC
x 31360)) and a pseudo horizontal sync at
TPG
9