Bit Banging s/w for MCP23S08 SPI & PIC16F877

[bassplayer]

I am starting to write software utilizing the Port I/O expander MCP23S08 using a bit bang SPI method. I usually do this until I see everything work then transfer over to the SPI functions of the PIC16F877. I'm having trouble though with the MCP23S08 not transmitting data to the 877. This must mean that I do not understand the fundamentals of the 23S08 yet. As such, I have a few general questions:

a) If I am going to transmit a Device Opcode from the 877 to the 23S08 do I send the MSB first? ie. 0100 0 A1 A0 R/W? Here is the bit bang code example with address A1=0 A0=0:

output_low(TDIP_CS); //
delay_us(50);

output_low(TDIP_CLK);
delay_us(50);
output_low(TDIP_DOUT); //opcode 0
delay_us(50);
output_high(TDIP_CLK);
delay_us(50);

output_low(TDIP_CLK);
delay_us(50);
output_high(TDIP_DOUT); // opcode 1
delay_us(50);
output_high(TDIP_CLK);
delay_us(50);

output_low(TDIP_CLK);
delay_us(50);
output_low(TDIP_DOUT); // opcode 0
delay_us(50);
output_low(TDIP_CLK);
delay_us(50);

output_low(TDIP_CLK);
delay_us(50);
output_low(TDIP_DOUT); // opcode 0
delay_us(50);
output_low(TDIP_CLK);
delay_us(50);


output_low(TDIP_CLK);
delay_us(50);
output_low(TDIP_DOUT); // opcode 0
delay_us(50);
output_low(TDIP_CLK);
delay_us(50);

output_low(TDIP_CLK);
delay_us(50);
output_low(TDIP_DOUT); //a1
delay_us(50);
output_high(TDIP_CLK);
delay_us(50);

output_low(TDIP_CLK);
delay_us(50);
output_low(TDIP_DOUT); //a0
delay_us(50);
output_high(TDIP_CLK);
delay_us(50);

output_low(TDIP_CLK);
delay_us(50);
output_high(TDIP_DOUT); //read bit = 1 write bit = 0
delay_us(50);
output_high(TDIP_CLK);
delay_us(50);


b) Can the CS signal stay low the entire transmission of the OPCODE byte, ADDRESS byte, and DATA byte?

c) I only want to use the MCP23S08 to read 8 DIP switches. Upon device RESET, the device automatically comes up configured for input. I attached an R/C filter to the RESET pin to allow the device to properly RESET. If my only use is to poll the GPIO Port via a bit bang method then I would assume I would send the OPCODE 0100 0001, ADDRESS BYTE 0000 1001, and then read the DATA BYTE from the MCP23S08? Or do I need to configure each register in software?

Thanks for the help!!!

[Ttelmah]

First comment, use 1uSec (or preferably one _cycle_) delays, rather than 50Sec. The MCP23x08, supports clock rates up to 10MHz...
Second comment get into thinking about sending the data by shifting it out of a single byte, and not having to work 'bit by bit'.
Third, get the data sheet. It shows the data format, including which order the bits need to be sent, and how the CS line should be operated. Pages 26&27.
Something like:

[bassplayer]

Couldn't ask for anything more. Thanks again!!!