Hi,
The following procedure is used to check the operation using TL16C752C. However, we are unable to obtain the values as expected.
(1) A telegram (0xFF)(0x30)(0x30)(0x30)(0x30) is sent from the lower board every 500ms. Due to the specification of the lower board, the telegrams are output one character at a time. The multi-analyzer shows the message as a single sentence, and there is no interval between characters.
(2) The upper board receives the above message on RXA/RXB.
(3) The register of TL16C752C is not changed.
(4) At the timing when the message from the lower board is received two or more times, the upper board specifies A[2:0] = 010 to 100, sets IOR = 1 to 0, and acquires D[7:0] = 0x30.
(5) Result of acquisition
A[2:0] = 010 : D[7:0] = 0000 0001 = 0x01
A[2:0] = 011 : D[7:0] = 0001 1101 = 0x1D
A[2:0] = 100 : D[7:0] = 0000 0000 = 0x00
The multi-analyzer confirms that the message from the lower board can be received at the RXA/RXB tangent. The values obtained with A[2:0] = 010~100 are different, and the values are the same with TL16C752C, which does not have RXA/RXB connected. Therefore, I believe that TL16C752C is not receiving the telegram, but I do not know the cause. Can you give me some advice?
Thanks,
Conor
