Fast command packets

Supported fast commands from CCC:

• 0xE311 - start of acquisition
• 0xE313 - stop of acquisition
• 0xE000 - synchronization fast command (DIF synchronizes its internal 5MHz divided clock to the arrival of this command)
• 0x0000 - command to reset the LVDS buffer (not needed anymore).

Thise commands are transmitted serially. The communication protocol is a UART-like, 1 start bit, 16 data bits, no parity and 2 stop bits. Example of transmitting a fast command 0xE311:

Fast commands can be send from the mini-LDA directly (not wing-LDA). LDA accepts following format (Start acquisition example):

bytes #0-3 are fixed length (2 byte), bytes 5 and 4 are the fast command. Additional zeroes (as byte 6 and 7) are needed when sending directly to the character node in petalinux.

LDA TCP packets (PC → LDA → DIF)

The LDA accepts DIF standard packets in following format:

Length: the length of the following packet (length field itself doesn't count). Little endian (LSB is on byte index 0)

type: should be 02

port: address where will be the packet sent

LDA address space

LDA registers can be addressed using a dedicated port2 values: 0x80 (read from the register) and 0x83 (write to the register). The format is same for both and write. LDA responses to this command.

• Length: fixed to 0x08 for these packets
• type: must be 2
• port: 0x80 = read from the address, 0x83 = write to the address
• addr: address to the configuration register
• dest: either a port number (0..95), or FPGA system ports (0x80, 0x81, 0x90)

Port configuration address space:

Address registers:

addr 0x0000  (index 0) port enable 
              bit 0: CONFIG_PORT_ENABLED
addr 0x0002  (index 1) configuration
              bits 2..0: CONFIG_RX_TIMEOUT0
              bits 6..4: CONFIG_RX_TIMEOUT1
              bit 8    : CONFIG_RX_MERGE_ROP               
addr 0x0004  (index 2) status
              bit  0     : STATUS_RX_IDLE                
              bit  1     : STATUS_RX_CRC_OK                         
              bits 10..8 : STATUS_RX_FSMSTATUS           
addr 0x0006  (index 3) status
              bit  0    : ERROR_RX_PACKET_FORMAT ;                
              bit  1    : ERROR_RX_PACKETID;                  
              bit  2    : ERROR_RX_PACKET_ORDER;              
              bit  3    : ERROR_RX_CHAINSOURCE_MISMATCH;      
              bit  4    : ERROR_RX_TIMEOUT0;                  
              bit  5    : ERROR_RX_TIMEOUT1;                  
              bit  6    : ERROR_RX_LENGTH_OVERFLOW;           
              bit  7    : ERROR_RX_CRC;                       
              bit  8    : ERROR_RX_INVALID_STATE;             
              bit  9    ; ERROR_RX_POINTER_OVERWRITTEN;       
addr 0x0008 (index 4) idelay  (TODO)
addr 0x000A (index 5) odelay  (TODO)
addr 0x000C (index 6) 
addr 0x000E (index 7) 

Mini-LDA system configuration address space:

Address registers:

addr 0x00 (index0) config
    bit 0: busy extend 1 - extend the busy until the packet Queue is read out (last packet might be still in progress)
    bit 1: busy extend 2 - extent the busy until the DMA fifo get empty. Not implemented
    bit 15: initiate a reset. no reply on this message
addr 0x02 (index 1)
    bits 9..0 busy signals of the 
addr 0x04 (index 2) -- reserved for wing-lda
addr 0x06 (index 3) -- Readout  cycle

LDA TCP packets (LDA → PC)

Header

All packets from LDA have a following 8-byte header:

The 16-bit length indicates the length of the remaining data. It should be <4k and should be an even number.

Timestamping packets

Header → status is 0x0800

Header → port# is usually 0xA0

TS_types:

• 0x01: acq start
• 0x02: acq stop
• 0x03: sync packet
• 0x10: new trigger
• 0x11: new ROC (caused by acq_stop)
• 0x20: busy rising edge (TODO check the polarity)
• 0x21: busy falling edge(TODO check the polarity)

ROC/trig# is a shared field, which shows the readout cycle except for the trigger event, where a trigger number is stored instead.

ASIC Readout packets

Wing-LDA 8b10b code extension

The wing-LDA is internally using the FPGA ↔ FPGA link, which uses 8b10b natively, using following commands. 2 words are transmitted in parallelAdditional to this, Wing-LDA is internally using