This week I continue the work on the SSL. After I included all the necessary files, it return errors of ‘TCB_uRam’ cannot fit the section. At first I thought it was running out of RAM space like another case that I experience before. Since the SSL is a very large file, therefore I disable all the unnecessary stack. However, after disabling most of the stack it still return the same error. By referring on the datasheet, it seems that the error was not out of memory space. After do further searching, I found that the problem might due to the MPLAB C18 compiler cannot create a single RAM object larger than 256 bytes, therefore it return the uRam error. I tried to refer on some the some link to merge the large fille to use more data section. However, it was difficult for me and at last the problem remain unsolved. Below is the reference link on the udata error solution. http://www.xargs.com/pic/c18large.html
Before that there were problems to call some of the MPLAB C18 libraries. Hence I needed to include all the library files manual to use the necessary functions. After that, I run the programs to check whether there are possible errors to call the functions. At first there was one function cannot being call properly, but after include the headers correctly the problem disappear. I used HTTP to perform some testing code of SPI and USART, and it was able to perform the operation correctly.
Next, I need to test the TCP performance. Since there was a TCP Performance Testing in the stack, I used it to test the speed by adjusting different buffer size. I test it from the buffer size of 100 to 1900. Since the default maximum size is 3900, I set the maximum range to 1900, by considering both the RX(1900) and TX(1900) pins have the same value. For the RX pin TCP test, it require to upload a large data file to the port to test on the speed. I created a large dummy file, and use netcat to upload it to the performance testing port. After uploading, it return the speed of each second in the terminal. However the works haven’t complete and the next week will continue on it.