diff options
Diffstat (limited to 'doc/protocols')
| -rw-r--r-- | doc/protocols/ihu-ttx.txt | 22 |
1 files changed, 11 insertions, 11 deletions
diff --git a/doc/protocols/ihu-ttx.txt b/doc/protocols/ihu-ttx.txt index 2fc518c..2260968 100644 --- a/doc/protocols/ihu-ttx.txt +++ b/doc/protocols/ihu-ttx.txt @@ -6,13 +6,13 @@ Bitstream --------- IHU and TTX communicate using a simple serial synchronous bus (SDA,SCL). -The IHU is the master and drives the clock. On Idle the SCL and SDA are both -at logic 0. When the IHU want's to communicate it has to generate wakeup pulse +The IHU is the master and drives the clock. On idle the SCL and SDA are both +at logic 0. When the IHU want's to communicate it has to generate a wakeup pulse with a minimun length of 1µs. After this it has to wait at least 3ms for the TTX -wake up and switch to a higher oscillator frequency. The data is transferred in -octets MSB first. SDA must be stable before the clock goes high. A Clock pulse -must be at least 4µs long and the data has to stay valid for at least 17µs. After -each octet there must be a break of 50µs. +to wake up and switch to a higher oscillator frequency. The data is transferred +MSB first in groups of 8bits (1 Octet). SDA must be stable before the clock goes +high. A Clock pulse must be at least 4µs long and the data has to stay valid for +at least 17µs. After each octet there must be a break of 50µs. | wake up | 1st octet | break | 2nd octet _________________ _________________ @@ -29,11 +29,11 @@ Frames ------ Every frame starts with 4 bit command code and a 4 bit length field. After this follow -len octets of data. When all the data has been transferred the Master (IHU) switches -SDA as input and clocks in on byte as acknowledge. The aknowledge is a one byte XOR +len octets of data. When all the data has been transferred the master (IHU) switches +SDA to input and clocks in on byte as acknowledge. The aknowledge is a one byte XOR checksum over all octets (including the command/len octet). -Field-length: 1 LEN 1 +Field-length: 1 LEN 1 +---------+----------------+--------+ Name | CMD/LEN | DATA | CS | +---------+----------------+--------+ @@ -68,7 +68,7 @@ Commands Hex 'A' ~~~~~~~ - This instructs the TTX to send out a aknowledge frame over cw. The command + This instructs the TTX to send out an aknowledge frame over cw. The command has 1 octet of data containing the ASCII Code of the aknowledge to send out. Hex 'B' @@ -76,7 +76,7 @@ Commands This inscructs the TTX to send out a beacon immediately. It also resets the timer so that the next beacon will follow after the normal beacon period. This command has - no data + no data. Hex 'F' ~~~~~~~ |