Distinction of input data </TITLE> </HEAD><BODY> <P> <A HREF="pr9-2-3.htm"> Return to previous page </A> | <A HREF="../index.htm"> Return to menu </A> | <A HREF = "pr9-3.htm"> Go to next page </A> </BR> </P> <HR> <H3> Determining input data </H3> <P> The input information from the device is determined by comparing the peripheral data described above with the assignment data described below. <BR> The assignment data is defined in the header file “sl_def.h” attached to the system. For example, the assignment corresponding to each input device of Saturn PAD is defined as follows. </P> <H4> Figure 9-5 #define value of assignment data (Saturn PAD) </H4> <IMG SRC="p09-06-1.gif"> <P> Since these assignments are used for collation with peripheral data, they correspond to the peripheral data length of each device. For example, the A button assignment for Saturn PAD is expanded as shown in the following figure (16-bit length). In the assignment data, the bit corresponding to the input device to be identified is set to 1, and the other bits are set to 0. </P> <H4> Figure 9-6 Pad assignment contents (PER_DGT_TA) </H4> <IMG SRC="p09-06-2.gif"> <BLOCKQUOTE><P> Note) Only the same bit (10th bit) that operates when the A button is input is 1. </P></BLOCKQUOTE> <P> In the case of Saturn PAD, the input device consists of simple switch ON / OFF, so the switch status can be confirmed by logical operation of assignment data and peripheral data. </P> <P> Figure 9-7 shows an example of checking the input status by AND operation of peripheral data and assignment data. If the input device specified by the assignment data is ON, 0 is output as the operation result. </P> <P> This method is also adopted in the sample program, and it is designed to display a sprite on the screen if the input device pointed to by the pad assignment is ON. </P> <H4> Figure 9-7 Confirmation of input status using assignment data </H4> <IMG SRC="p09-07.gif"> <P> In this example, data is collated by AND operation of peripheral data and assignment data, but it is not always necessary to adopt this method. </P> <HR> <P> <A HREF="pr9-2-3.htm"> Return to previous page </A> | <A HREF="../index.htm"> Return to menu </A> | <A HREF = "pr9-3.htm"> Go to next page </A> </BR> </P> </BODY> </HTML>