Hi Steven,
Thanks for your expert advice.
I`m just programing TNT4882 working in Programmed-I/O mode (not DMA) to transfer
data. The code for Programmed-I/O is coded following ESP-488 source code(NGPIB_IO.c and
EX5.c) (http://joule.ni.com/nidu/cds/view/p/id/223/lang/en) in the dir of ESP-488\NOTNT\ as
an example, referencing Chapter 4 in TNT4882 Programmer Reference Manual. I`m sorry I cannot
show you original source code, but I would show my register-configuration sequence to you.
The offsets of all the registers in TNT4882 in our device is just as twice as the
offsets specified in page 3-2, 3-3 of TNT4882 Programmer Reference Manual. So the offset of
FIFOB would be 0x30, then FIFOA is 0x32. In TNT4882 reading and writing, I use 16-bit mode
to read and write data. When I read data from TNT4882, I first read FIFOB then FIFOA to get
a complete word, and I can get the right data from TNT4882. As same as the reading, when I
write data to TNT4882, I first write the 1st byte to FIFOB, then the 2nd byte to FIFOA to send a complete word. Here maybe it has something wrong with my operation when I write data.
Now I would show the write-data code sequence:
When I detect the TNT4882 is in Talker mode from ADSR, I will call the initializing writing
code for writing-data-transfer:
TNT_Out(R_cmdr,F_resetfifo);
TNT_Out(R_cnt0, (char)(twos_cnt)); /* Load twos compliment count */
TNT_Out(R_cnt1, (char)(twos_cnt>>8)); /* into TNT count registers */
TNT_Out(R_cnt2, (char)(twos_cnt>>16));
TNT_Out(R_cnt3, (char)(twos_cnt>>24));
TNT_Out(R_imr0,B_glint); /* Set write to imr0 to be sure */
TNT_Out(R_auxmr,HR_auxrj|0); /* B_to is cleared */
TNT_Out(R_imr1, B_err); /* End transfer on err */
TNT_Out(R_eosr, 0); /* Set EOS byte */
TNT_Out(R_auxmr,HR_auxra|F_hlda)
TNT_Out(R_cfg , (B_tlchlte|B_16bit)); // I don`t set time-out attribute.
TNT_Out(R_auxmr,F_hldi); /* Hold off immediately */
TNT_Out(R_cmdr, F_go);
--------------------------------------------
During the writing-data-transfer, I use the status of END|EOS|ERR|B_done|B_tlcint to
control the data transfer. Such as if I transfer the "ACER\n", I write the data out use the
following code(16-bit mode):
TNT_Out(FIFOB,'A');
TNT_Out(FIFOA,'C');
TNT_Out(FIFOB,'E');
TNT_Out(FIFOA,'R');
TNT_Out(FIFOB,'\n');
--------------------------------------------
After aborting transfer of writing:
TNT_Out(R_cmdr,F_stop);
TNT_Out(R_cmdr,F_resetfifo);
if(TNT_In(R_isr1)&B_end) /* If we received an END */
TNT_Out(R_auxmr,F_clrEND); /* Clear status bit */
if(TNT_In(R_isr1)&B_err) {
TNT_Out(R_auxmr,F_clrERR); /* Clear error bit */
if(io_type==OUTPUT) {
TNT_Out(R_hssel,F_onechip|B_go2sids); /* if error set to idle state. */
}
-------------------------------------------
I have to notice that during the chip-initializing after power on, I set the T1 delay to 1100ns.
Thanks for your great help again.
Have a good day.
