diff options
Diffstat (limited to 'spi/sqi')
| -rw-r--r-- | spi/sqi/README | 48 | ||||
| -rw-r--r-- | spi/sqi/sqi-four-data-lines-one-transfer.sr | bin | 0 -> 695 bytes | |||
| -rw-r--r-- | spi/sqi/sqi-four-data-lines-three-transfers.sr | bin | 0 -> 746 bytes |
3 files changed, 48 insertions, 0 deletions
diff --git a/spi/sqi/README b/spi/sqi/README new file mode 100644 index 0000000..89736fc --- /dev/null +++ b/spi/sqi/README @@ -0,0 +1,48 @@ +------------------------------------------------------------------------ +SQI communication (multi-I/O SPI) +------------------------------------------------------------------------ + +This capture demonstrates SQI communication, which is a form of SPI data +exchange where transmitters use multiple I/O data lines in parallel to +communicate the same amount of data in fewer clock cycles. + +In contrast to e.g. QuadSPI flash memory chips which may change the data +line count or clock scheme several times within a transaction, SQI keeps +the clock and the number of data lines used by the transmitter consistent +across the full length of the SPI transaction. Only the direction of data +lines could change, when e.g. a master first transmits a request which +the slave then responds to, while both use the same number of data lines. +Full duplex communication as with the traditional MISO/MOSI scheme is +not possible with SQI. + + +Logic analyzer setup +-------------------- + +The capture was taken at a samplerate of 100MHz. + + Probe SPI + ---------------------------- + 2 SCK (clock) + 3 CS (select) + 4 IO0 (data, LSB) + 5 IO1 + 6 IO2 + 7 IO3 (data, MSB) + + +sqi-four-data-lines-one-transfer.sr +----------------------------------- + +This capture uses four I/O data lines. Data gets sampled at the rising +clock edge (single data rate). Data is sent in MSB first order. The SPI +transaction's data byte sequence is: + + 80 00 00 10 22 42 4f 4f 54 00 80 00 00 a8 85 77 00 20 4e 00 00 + + +sqi-four-data-lines-three-transfers.sr +-------------------------------------- + +This capture was constructed from the above single-transfer example +capture. The SPI transfer is repeated three times. diff --git a/spi/sqi/sqi-four-data-lines-one-transfer.sr b/spi/sqi/sqi-four-data-lines-one-transfer.sr Binary files differnew file mode 100644 index 0000000..be47f9b --- /dev/null +++ b/spi/sqi/sqi-four-data-lines-one-transfer.sr diff --git a/spi/sqi/sqi-four-data-lines-three-transfers.sr b/spi/sqi/sqi-four-data-lines-three-transfers.sr Binary files differnew file mode 100644 index 0000000..d75222a --- /dev/null +++ b/spi/sqi/sqi-four-data-lines-three-transfers.sr |