On Fri, 7 Mar 2003 11:35:02 -0500, Mark Stokes wrote: >I have a macro: >#define SPITXWAIT while ( !( IFG1 & UTXIFG0 ) ); // Wait for the TX >That is expanding to this:
> SPITXWAIT; // USART0 TX buffer ready? > 1994: c2 93 02 00 cmp.b #0, &0x0002 > 1998: fd 37 jge $-4 ;abs dst addr >0x1994 >Even though this is seeminging to work, why is UTXIFG0 being expanded to >"#0" instead of "0x80" as it should be. Here is the macro definitions >in the header file: >#define UTXIFG0 (1<<7) >Try as I might, I cannot get the cmp.b to compare w/ 0x80. It seems >stuck on only comparing Zero with IFG1. This also happens when I use >something else, like U0TCTL. Or if I use this macro definition: >#define SPITXWAIT while ( !( IFG1 & 0x80 ) ); // Wait for the TX >Any ideas? >-Mark It is not doing a bit test, it is checking if the value is negative i.e. if the high order bit of the byte is set -Bill Knight R O SoftWare
