PM2R_RD_PALETTE_WRITE_ADDRESS
pm2_WR(par, PM2R_RD_PALETTE_WRITE_ADDRESS, 0);
pm2_WR(p, PM2R_RD_PALETTE_WRITE_ADDRESS, idx);
pm2_WR(p, PM2R_RD_PALETTE_WRITE_ADDRESS, idx);
pm2_WR(p, PM2R_RD_PALETTE_WRITE_ADDRESS, 0);
pm2_WR(p, PM2R_RD_PALETTE_WRITE_ADDRESS, regno);