nrfxlib API 2.7.99
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◆ sdc_hci_cmd_le_read_buffer_size()

uint8_t sdc_hci_cmd_le_read_buffer_size ( sdc_hci_cmd_le_read_buffer_size_return_t p_return)

#include <softdevice_controller/include/sdc_hci_cmd_le.h>

LE Read Buffer Size [v1].

The description below is extracted from Core_v5.4, Vol 4, Part E, Section 7.8.2

This command is used to read the maximum size of the data portion of ACL data packets and isochronous data packets sent from the Host to the Control- ler. The Host shall segment the data transmitted to the Controller according to these values so that the HCI ACL Data packets and HCI ISO Data packets will contain data up to this size (“data” includes optional fields in the HCI ISO Data packet, such as ISO_SDU_Length). The HCI_LE_Read_Buffer_Size command also returns the total number of HCI LE ACL Data packets and iso- chronous data packets that can be stored in the data buffers of the Controller. The HCI_LE_Read_Buffer_Size command shall be issued by the Host before it sends any data to an LE Controller (see Section 4.1.1). If the Controller sup- ports HCI ISO Data packets, it shall return non-zero values for the ISO_Data_- Packet_Length and Total_Num_ISO_Data_Packets parameters.

If the Controller returns a length value of zero for ACL data packets, the Host shall use the HCI_Read_Buffer_Size command to determine the size of the data buffers (shared between BR/EDR and LE transports).

Note: Both the HCI_Read_Buffer_Size command and the HCI_LE_Read_- Buffer_Size command may return buffer length and number of packets param- eter values that are nonzero. This allows a Controller to offer different buffers and number of buffers for BR/EDR data packets and LE data packets.

The LE_ACL_Data_Packet_Length return parameter shall be used to deter- mine the maximum size of the L2CAP PDU segments that are contained in ACL data packets, and which are transferred from the Host to the Controller to be broken up into packets by the Link Layer. The Total_Num_LE_ACL_Data_- Packets return parameter contains the total number of HCI ACL Data packets that can be stored in the data buffers of the Controller. The Host determines how to divide the buffers between different connection handles.

The ISO_Data_Packet_Length return parameter shall be used to determine the maximum size of the SDU segments that are contained in isochronous data packets, and which are transferred from the Host to the Controller. The Total_Num_ISO_Data_Packets return parameter contains the total number of isochronous data packets that can be stored in the data buffers of the Controller. The Host determines how to divide the buffers between different connection handle(s).

Note: The LE_ACL_Data_Packet_Length and ISO_Data_Packet_Length return parameters do not include the length of the HCI ACL Data packet header or the HCI ISO Data packet header respectively.

Event(s) generated (unless masked away): When the HCI_LE_Read_Buffer_Size command has completed, an HCI_Command_Complete event shall be generated.

Parameters
[out]p_returnExtra return parameters.
Return values
0if success.
Returns
Returns value between 0x01-0xFF in case of error. See Vol 2, Part D, Error for a list of error codes and descriptions.