Other Parts Discussed in Thread: C2000WARE
TMS320F28388D
2、purpose：
I want to add an SDRAM memory to this chip.
3、problem：
（1）The GPIO_72 pin of the DSP is occupied by the Boot Mode Selection Switch.
At this time, the data bit D12 of the expanded SDRAM also needs to be connected to GPIO72.
（2）The GPIO_44 pin of the DSP is occupied by the pin of the ethernet.
At this time, the address bit A4 of the expanded SDRAM also needs to be connected to GPIO44.
（3）The GPIO_75 pin of the DSP is occupied by the pin of the ethernet.
At this time, the data bit D9 of the expanded SDRAM also needs to be connected to GPIO75.
4、Try a solution：
Attempt 1: (Only modify the conflicting address line and data line)
Connect the externally expanded SDRAM conflicting address line A4 to EMIF1_A13 (not connect to EMIF1_A4 according to the original SDRAM_A4).
Connect the conflicting data lines D9 and D12 of the externally expanded SDRAM to D16 and D17 of EMIF1 (not connected to EMIF1_D9 and D12 according to the original SDRAM_D9 and D12).
The connection method is as follows:
Attempt 2: (Connect the address line and data line of the SDRAM to the EMIF1 of the DSP as a whole in translation)
Connect the address lines A0-A12 of the externally expanded SDRAM to EMIF1_A5-A17
Connect the data lines D0-D15 of the externally expanded SDRAM to EMIF1_D16-D31
5、Questions to ask
If you choose the first connection method for the above two attempts, (only modify the conflicting address line and data line), do not modify the other address lines and data lines.
This connection method as shown in the figure below:
In this connection method, the address line and the data line are not correspondingly connected.
It is also convenient when the program is driven on the CCS side.
You only need to modify the pins in the code after the hardware is connected, as shown in the figure below.
The annotation looks like:
According to this modification, does it comply with the DSP's external expansion connection standard? Does it affect the normal use of SDRAM?
6、 The reasons for choosing Attempt 1 are：
It is convenient to modify the PCB diagram.
7、 What is your suggestion for modification?
I'm here to ask!
thanks!
