Register: Video scale register

DAT
< Label > < Condition > Instruction VSCL, SrcOperand < Effects >

DAT
< Label > < Condition > Instruction DestOperand, VSCL < Effects >

• Label is an optional statement label. See Common Syntax Elements.
• Condition is an optional execution condition. See Common Syntax Elements.
• Instruction is the desired assembly instruction. VSCL may be used in either the assembly instruction's DestOperand or SrcOperand fields.
• SrcOperand is a constant expression used by Instruction to operate on, and optionally write to, the VSCL register in DestOperand.
• DestOperand is a constant expression indicating the register that is operated on, and optionally written to, using the value of VSCL in SrcOperand.

Explanation

VSCL is one of two registers (VCFG and VSCL) that affect the behavior of a cog's Video Generator. Each cog has a video generator module that facilitates transmitting video image data at a constant rate. The VSCL register sets the rate at which video data is generated.

The following code sets the Video Scale register for 160 pixel clocks and 2,560 frame clocks (for a 16-pixel by 2-bit color frame). Of course, the actual rate at which pixels clock out depends on the frequency of PLLA in combination with this scale factor.

                  mov      vcfg,  VscCfg 
VscCfg    long    %000000000000_10100000_101000000000 

See Registers and the Spin language VSCL for more information.