HmuSoftwareSpec

intro

several general purpose functions will be utilized to built applications using the hacked mouse.

Syncronous Serial Port

Interrupt on Pin Change

Generate an interrupt on the SCK rising edge and falling edge. This interrupt is used to capture the master clock signal coming from the USB chip

SCK Edge

Return whether the clock signal is rising or falling. This is important as the edge is used to either load data or latch data on the SDIO pin

ReadBit

do i really need to go that low?

WriteBit

do i really need to go that low?

ReadByte

wrapper around lower level functions to facilitate reading one byte from the master

• If the MSB is 1 then the master is performing a write operation
  • Store the 7bit address addr
  • Call ReadByte again to capture the data to write to addr
• If the MSB is 0 then the master is performing a write operation
  • Store the 7bit address addr
  • Call WriteByte to write the data stored in addr to the serial port

WriteByte

wrapper around lower level functions to facilitate writing one byte to the master

• Assume a read operation has already been called
• Load the data from addr and write it to the SDIO pin

-- ChristopherPepe - 23 Aug 2006