h6. [[OS SWI Calls]] h6(. » OS_IICOp h2. OS_IICOp h5. (SWI &7B) |_<^{width:4em}. Entry | | |<^. R0 |<^. Pointer to list of [[iic_transfer]] structures | |/2<^. R1 |<^. Bits 0-23: Number of iic_transfer structures | |<^. Bits 24-31: IIC bus number | |_<^{width:4em}. Exit | | |<^. - |<^. All registers preserved | |<^. - |<^. Transfer list updated, if applicable | h4. Use The purpose of this call is to allow software to perform transfers on the IIC buses that are present in the system. See the [[iic_transfer]] documentation for details on the transfer list format and behaviour. h4. Notes To determine how many IIC buses are present on the system, use [[OS_ReadSysInfo 14]]. OS_IICOp is re-entrant. Transfers are queued on a per-bus basis. Thus if OS_IICOp is re-entered then it will first wait for all pending transfers on the requested bus to complete before starting the set of transfers requested by the new call. OS_IICOp will enable interrupts for the duration of the transfer. This SWI is an improved, more powerful version of the older [[IIC_Control]] SWI. h4. See also * [[IIC_Control]] * [[iic_transfer]] * [[OS_ReadSysInfo 14]] * [[RISCOS_IICOpV]]