We have finally reached a consensus on the CUMP BUS rev. 1.0 (we've been in 0.x up until now)
Here's the 1st release revision of the CUMP bus:
VAR: Variable Voltage
VCC: Supply voltage (5V/3V?)
GND: 0V
BD: BiDirectional signal
PP: Parallel Port signal
E: Parallel Port Enable (aka parallel port clock)
RW: Parallel Port Read/Write signal
ALE: Parallel Port Address Latch Enable
SDA: IIC Serial Data
SCL: IIC Serial Clock
SDI: SPI Serial Data In
SCK: SPI Serial Clock
SDO: SPI Serial Data Out
VCLK: Variable Clock source
TX: UART data send (MB centric)
RX: UART data receive (MB centric)
IDC: Serial ID clock
IDD: Serial ID data
IDL: Serial ID load
IRQ: Interrupt Request
NC: Not Connected
The SDA and SCL lines may have to be put on the same lines as SDI and SCK repectively depending on the design and the MCUs available.
I think I forgot that the SPI protocol requires a #SS pin (slave select) that should be reflected in the next revision.
This section will grow larger, but due to the reprecussions of editing the very core of the CUMP architecture--the CUMP bus--nothing is solid right now.
See also:
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