SCSP has a serial interface for MIDI with a transfer rate of 31.25Kbps. However, since it does not have a "peripheral circuit for MIDI" and a "DIN connector for MIDI", it is not possible to create applications using MIDI. A MIDI interface block diagram is shown in Figure 4.53.
Figure 4.53 MIDI-I / F block diagram
MIBUF [7: 0] (R); Midi Input BUFfer
MIDI input data buffer. For reception on the MIDI-IN side, the data transferred from the outside is automatically taken into the MIDI-IN buffer "MIBUF".
MIOVF (R); Midi Input OVer-Flow
If data is transferred to MIDI-IN while all the MIDI-IN buffers are filled with data, "MIOVF" becomes "1B", indicating that overflow has occurred. Overflow causes a MIDI communication error because MIDI communication is not performed normally.
MIFULL (R); Midi Input FULL
If data is captured in all 4 bytes of the MIDI-IN buffer, "MIFULL" will be "1B", indicating that there is no free space in the buffer.
MOFULL (R); Midi Output FULL
Data output If all 4 bytes of the MIDI-OUT buffer contain data, "MOFULL" will be "1B", indicating that there is no free space in the buffer.
MOEMP (R); Midi Output EMPty
If all the data in the MIDI-OUT buffer is being ejected, or if no data is transferred to the MIDI buffer, "MOEMP" will be "1B", indicating that the buffer is empty. At the same time, it is possible to notify the CPU that it is empty by interrupting.
Figure 4.54 shows MIDI-OUT and the interrupt generator.
Figure 4.54 MIDI OUT section and interrupt generator section
MOBUF [7: 0] (W); Midi Output BUFfer
MIDI output data buffer. For MIDI-OUT transfer, write the data you want to transfer to "MOBUF". After that, the data will be transferred automatically.
