vcc_txreadptr
TXREADPTR_GET_PTR(cardvcc_read(lvcc, vcc_txreadptr)));
endptr = TXREADPTR_GET_PTR(cardvcc_read(lvcc, vcc_txreadptr));
cardvcc_write(lvcc, 0, vcc_txreadptr);
read = TXREADPTR_GET_PTR(cardvcc_read(lvcc, vcc_txreadptr));
cardvcc_write(lvcc, 0, vcc_txreadptr);