2.2.2 BER Receive Test Mode Setup

The BER Receive Test mode is set up using register A21 (GPO test register) with the following settings:
Table 2-5. A21 Register Configuration Settings
Bit#NameDescription
32GPO_select[5]
  • I: Test modes for the GPO pins
  • O: Test outputs

(default: 0)

31GPO_select[4]
30GPO_select[3]
29GPO_select[2]
28GPO_select[1]
27GPO_select[0]
23DIG_PN_Stream

1 = Enables the BER Test mode; the devices must be in TX and RX modes; TX sends PN31 data (ITU-T 0.150 (05/96))

RX checks the accuracy of the sequence; if there is an error, the GPO pin is set; the PN generation starts with the TX/RX mode. Apply a power-down sequence to exit.