Type 0:
*Bits 7..4 define Vertical Sync Width. If 0 is programmed this gives 16 lines of VSYNC.
*Bits 3..0 define Horizontal Sync Width. If 0 is programmed no HSYNC is generated(and therefore, no interrupts).
Type 1:
*Bits 7..4 are ignored. Vertical Sync is fixed at 16 lines.
*Bits 3..0 define Horizontal Sync Width. If 0 is programmed no HSYNC is generated(and therefore, no interrupts).
Type 2: