hi,

This is not working.

How did you determine that it doesn`t work? What value is received (0x00, 0xff, ..?).

If you sure that the problem is because two wires are tied together then you should solve it with using open-drain buffer for MOSI (either with SN7407 or with transistors). It prevents strong high level output. I doubt that it is the problem but who knows? Maybe MCU utilizes strong pull-up for alternative functions of a pin, maybe not. I have no such info.

Another solution is to replace hardware SPI receiver with software routine. This way, you send byte to MAX6662 as always (using hardware transmitter). Then read it through MOSI with software-emulated clock on SCK bit-by-bit. Yes, it annoys alot but does not require additional external hardware.

Regards,
Oleg