2.5.3.3.2.2 Uplink Credit Based Flow Control (UCBFC)

The procedure is used by a Transparent Client to enable Uplink Credit Based Flow Control on the Transparent Server. Once it is enabled, Server role can only send data to Client while the credit count is greater than zero.

When enable Uplink Credit Based Flow Control, Client shall write “Uplink Credit Based Flow Control Enable” opcode (0x15) to the Transparent Control Point on Transparent Server. There are given Credit value parameter in this opcode. Transparent Server will check the credit count to know how many packets can be uploaded to the Transparent Client by performing the notify operation to TUD Characteristic handle. The Credit count will be decreased by the number of ATT packet sending by Transparent Server. Transparent Server can send data only while the credit count is greater than zero. Transparent Client shall return the credit value to Transparent Server after the received data has been processed completed.

When enable Credit Based Flow Control Uplink and available credits on Client shall be written to the Transparent Control Point on Transparent Server. Transparent Server will check the number of credit to know how many available data list can transmit to the Transparent Client. The number of credit is decrease by the list of data sending by Transparent Server. Transparent Server is able to send data only while the number of credit is non-zero. Transparent Client shall return the credit to Transparent Server after the received data has been processed completed.