7

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7.0 Results

7.1 Distortion test.

The input to the ADC was connected to a 0-5 V 1MHz sine wave. The data was sampled. A test algorithm was used to load the data into the microprocessor. The data stored in the microprocessor was then dumped to a file using the debugger. The file was loaded in to excel and the graph produced is shown below.

Show below is a graph showing a 1MHz sine wave, sampled by the sampler at 20MHz

Graph 1.0 A Pure 1MHz sine wave.

From the above graph it can be seen that a 1MHz sine wave can be successfully sampled, and is not affected by noise or other distortion. This shows that the memory interface circuit works correctly.

7.2 Load Line Test.

A break point was added to the main assembly algorithm just after the load line stage. The contents of the memory table containing the raw data was dumped to file using the debugger and loaded into Excel. A graph of the data produced is shown below.

Graph 1.2 A line of PAL data.

From the above graph it can be seen that the load line algorithm waits for the start of a new line before storing the data, this is because the colour burst is at the start of the line.

By producing a graph of the colour burst it can be seen that a 4.4MHz signal can be sampled without distortion. A graph of the colour burst captured by using the same method as above is shown below.

Graph 1.3 A PAL colour burst

7.3 Hardware Phase 2

Extra memory and frame synchronisation.

The results for the phase 2 hardware are as above. The phase 2 hardware has two added functions, frame synchronisation and more memory. The results of this is that the sampling process does not start until the start of a new frame and also more lines of image can be sampled. The results of this was successful and can be seen in the Windows results section.

7.4 Triple byte EPP IRQ interface

A test was one to ensure that the interface hardware between the microprocessor and the PC Works correctly. The hardware should allow three bytes to be transmitted with one transmission request by making use of the wait line. A test algorithm was loaded that sent three bytes with each request, but incremented the value of each byte sent by one value. The results of this are shown below. See appendix n for the test code.

Table 1.0

IRQ Pixel request	Data Loaded
1	1,2,3
2	4,5,6
:	:
83	247,248,249
84	250,251,252
85	253,254,255

From the above graph it ca be seen that large amounts of data (255 bytes) can be transmitted and each byte will remain perfectly synchronised. This shows that this method of transmission will allow colour data to be transmitted easily.

7.5 Phase lock test

A break point was added to the phase lock algorithm at the point just after the comparisons were made. This allowed observations of the phase lock algorithm to be made. For this test a reference sine wave was stored in memory, that has an equal frequency and a similar magnitude to the burst wave to be sampled.

The program was executed and the algorithm was able to check the reference wave for a matching set of data values and then return the offset value required to match the data. An error of 10 was allowed, with 7 checks.

Burst Data	89	75	42	53	93	86	49
Reference Data	55	71	88	78	57	60	82	87	67	55	70	88	78	57	60	81	87	67
Error Values	n/a							2	8	0	0	5	8	0	n/a
Offset	0	1	2	3	4	5	6	7	8	9	10	11	12	13	14	15	16	17

From the above table it can be seen that a match was found with a offset of 7.

Shown below is a series of tests, showing the burst data on the top row and a series of matches with the offsets required.

Burst Data	66	83	81	46	52	74	offset
Match 1	63	88	73	47	47	79	15
Match 2	62	88	74	46	46	78	24
Match 3	61	88	74	45	45	77	33
Match 4	60	87	75	45	45	77	42

The above results show that the phase locking algorithm can find and select matching number sequences and then return the offset value required to produce that match.

7.5 U+V Calculation

This test was done to ensure that the Raw data was correctly processed and U and V data was correctly produced. A break point was added just after the U + V calculation stage and the data was dumped to Excel.

Shown below are the results of the TMS320 DSP algorithm. The data processed was the raw data shown in the graph below.

The sine demodulated signal shows that the colour burst is much more in phase with the sine demodulation table that the rest of the signal because it is much higher in magnitude during the colour burst. This shows that the algorithm produces different values depending on the phase relation ship with the respective sine and cosine tables.

7.6 C++ Object Windows Linking (OWL)

Shown below are images that have been plotted to screen using the C++ program. This is probably the best way of showing that the algorithm works, because of it did not then the images could not have been produced.

Nintendo 64 images

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