The pixels in the test mode is generated as walking 1’s for each line.
Transmission LP sequencing
The simulation and Reveal debugging shows the correct 11-01-00-11(out of picture) sequence.
Before each line, there is a short transmission, featured on the left of the debugging waveform. This corresponds to the SoT (Start of Transmission) package.
857 Figure 31 shows the structure of the Low Level Protocol Short Packet. A Short Packet shall be identified by 858 Data Types 0x00 to 0x0F. See Table 3 for a description of the Data Types. A Short Packet shall contain 859 only a Packet Header; a Packet Footer shall not be present. The Word Count field in the Packet Header 860 shall be replaced by a Short Packet Data Field. 861 For Frame Synchronization Data Types the Short Packet Data Field shall be the frame number. For Line 862 Synchronization Data Types the Short Packet Data Field shall be the line number. See Table 6 for a 863 description of the Frame and Line synchronization Data Types. 864 For Generic Short Packet Data Types the content of the Short Packet Data Field shall be user defined.
Frame Synchronization Packets
1035 For FS and FE synchronization packets the Short Packet Data Field shall contain a 16-bit frame number. 1036 This frame number shall be the same for the FS and FE synchronization packets corresponding to a given 1037 frame.
1090 The Line Blanking Period is not fixed and may vary in length. The receiver should be able to cope with a 1091 near zero Line Blanking Period as defined in [MIPI01]. The transmitter defines the minimum time for the 1092 Frame Blanking Period. The Frame Blanking Period duration should be programmable in the transmitter.
Line Synchronization Packets
1046 Line synchronization packets are optional. 1047 For Line Start (LS) and Line End (LE) synchronization packets the Short Packet Data Field shall contain a 1048 16-bit line number. This line number shall be the same for the LS and LE packets corresponding to a given 1049 line. Line numbers are logical line numbers and are not necessarily equal to the physical line numbers
Multiple of 4…
Bit order in transmission follows the general CSI-2 rule, LSB first.
Drive LP from 11 – 01 – 00 and hold, until the receiver engage its termination resistor (how long for iMX6?). In the meanwhile TX engage HS driver, and disable LP driver. Beyond Td-term-en, 0 is injected in to HS lanes, for a certain time. Then a sync sequence is generated where communication starts.
UI Unit Interval, equal to the duration of any HS state on the Clock Lane The unit interval (UI) is one half of the period of the HS clock; at 500 MHz the minimum setup and hold time is 150 ps.
toggle the data and hold, until the LP-11 kicks in.
Leaving Pull Mode / Drive Mode Blank Causing Problem
LP pins were malfunctioning and keep giving floating voltage at all time. The problem is resloved when we set Pull Mode explicitly to DOWN mode, and Drive Current to 8.
Therefore, it is always advisable to set required parameters in exlicit commands, other than depending on the default value. They may not be implemented correctly.