Directed Write and Read Transfers
The Directed CCC Write/Read transfers are initiated on the bus based on the COMMAND_PORT settings as shown in the following table.
| Command Attribute | Field Name | Programmed Value | Description |
|---|---|---|---|
| Transfer Command | CP | 1 | Indicates to the I3CC to consider the CMD field. |
| CMD[14] | 1 | Indicates to the I3CC that the transfer is Directed CCC transfer. | |
| CMD[13:7] | 0x0 - 0x7F | Indicates the CCC command to be transferred. | |
| I2CNI3C | 0 | Indicates if the target is I2C (1) or I3C (0) only used in configurations with no DAT or DCT reserved otherwise. | |
| DEV_INDEX | DEV_INDEX | Indicates the Index of the Device Table which consists of the target address. | |
| MODE | 0 (SDR0) | Indicates to the I3CC that the transfer must go in SDR mode. All CCC transfers are initiated with SDR0 Speed. | |
| CMD_ATTR | 0 or 1 | 0: Indicates to consider the transmit data from the Transmit FIFO if RnW is set to ‘0’. 1: Indicates to the I3CC to consider the transmit data from the command if RnW is set to ‘0’. | |
| RnW | 0 or 1 | 0: Indicates the transfer is write transfer. 1: Indicates the transfer is read transfer. | |
| Regular Transfer (CMD_ATTR=0) | DATA_LENGTH | 0 - 65535 | Indicates the transfer length of the transfer. |
| Immediate Transfer (CMD_ATTR=1) | BYTE_CNT | 0 to 4 | Indicates the respective data bytes of the Immediate command are valid. |
The data in the transmit FIFO (Regular transfer) or data bytes (Immediate Data transfer) are not required for some directed write CCCs which do not have payload data indicated through DATA_LENGTH (Regular transfer) or BYTE_CNT (Immediate transfer). If the directed CCC does not consist of a payload, this must be indicated by ‘0’ in either DATA_LENGTH or BYTE_CNT fields based on the command issued.