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Hi,
I have read your release library project " PM_tformat_lib" for T format interface encoder in C2000ware-MotionControl-SDK. In your sample library, you create - configure TILE1 block and using CLB4 module for this TILE block. With module CLB4 - TILE1, there are 3 CLB outputs:
- Out2 - GPIO7 - PWM4B - Clock to SPI,
- Out3 - connect to In7 - output enable for PWM4B
- Out4 - TxEN - connect to OUTPUT Xbar
My project needs to read two t format encoders, so i need to create and configure one more TILE block ( ex TILE0,.....) which implement the same to TILE1 above.
My concern: Is it OK if I still use CLB4 for this new TILE (because I want to use PWM4A - GPIO6 - for CLB Out2 and Out3, Out4 the same to TILE1) or I have to use other CLB module for this new TILE as CLB1, CLB2 or CLB3..?
Dear Lori Heustess,
Thanks for your response, now I understand my issue. But I still have another concern. I am also building project which read data from Nikon A format encoder.
In my previous post, I asked about using CLB of C2000 to read Nikon A- format encoder and you recommend leverage open - source code from release library for T - format.
In source code for T format there is function which set up value for Match1, match2 and R0 register in Counter, HLC:
tformat_configureCLBLen((PACKET_BITS + 2), sendClks,receiveClks + dummySPIClks);
with sendClks = ABIT + PACKET_BITS + IDLE_BITS; and receiveClks = n * PACKET_BITS ;
the definition:
#define PACKET_BITS 10
#define IDLE_BITS 7
#define ABIT 1
I understand the defined values for ABIT, PACKET_BITS, IDLE_BITS and parameter sendClks, receiveClks pass into tformat_configureCLBLen () function
are based on T format protocol rule ( data length, send - receive timing, baudrate) - figure below:
But because I don't have the detail T format specification protocol, so I am confused when leverage when code for Nikon A format,
With my Nikon A format encoder: each transmission frame has length 18 bit, baudrate is also 2.5Mbs, and has signal timing like picture below
t1 = 7.2us (18 bit command), t2 = 1us(min), t3 = 1.5us(min), t5 = 3us, t6 = 21.5us (in this case three field- 18 bit data), t7 = 200ns = t8.
I don't understand clearly how to calculate the define value for IDLE_BITS and ABIT
So Is that ok if I do below:
#define PACKET_BITS 18
#define IDLE_BITS 7 =>> ??
#define ABIT 1 ==??
sendClks = ABIT + PACKET_BITS + IDLE_BITS; and receiveClks = 3 * PACKET_BITS ;
tformat_configureCLBLen((PACKET_BITS + 2), sendClks,receiveClks + dummySPIClks);
Thanks
Lori,
Sorry for upload screenshots that not come through.
Here screenshots are:
State Transiition
1, 
A format protocol and timing:
Which is: t1 = 7.2us (18 bit command), t2 = 1us(min), t3 = 1.5us(min), t5 = 3us, t6 = 21.5us (in this case three field- 18 bit data), t7 = 200ns = t8
Thanks,
Long Pham Tan said:1. About the defined value for ABIT, and IDLE_BITS, can you explain more about them? ( I mentioned in previous reply)
In the t-format document, Figure 9 has a timing diagram.
Hopefully this will help:
Long Pham Tan said:2. About the hardware the difference I see your TIDM-1011 board using IC SN 65HVD78 as transceiver ( Which uses 3.3V supply voltage), but with my owned designed board I used IC SN75176 as transceiver (which uses 5 V supply voltage ). Is that oK?
As long as it meets the voltage requirements of your components/encoder.
Regards
Lori
