PC87393VJG National Semiconductor, PC87393VJG Datasheet - Page 96

• Manufacturer Part Number: PC87393VJG
• Description: IC, SUPER I/O DEVICE, TQFP-100
• Manufacturer: National Semiconductor

Specifications of PC87393VJG

• Data Rate: 2Mbps
• Supply Voltage Range: 3V to 3.6V
• Logic Case Style: TQFP
• No. Of Pins: 100
• Operating Temperature Range: 0°C to +70°C
• Termination Type: SMD
• Transceiver Type: Interface
• Rohs Compliant: No

6.0 Musical Instrument Digital Interface (MIDI) Port
Note: This section applies to the PC87393 and PC87393F only.
6.1 OVERVIEW
This chapter describes a generic MIDI Port. For the implementation used in this device, see the Device Architecture and
Configuration chapter.
The MIDI Port is an asynchronous receiver/transmitter that uses a two-wire, bi-directional, relatively slow communication
channel to transmit and receive data bytes to or from MIDI-compliant devices, according to a predefined communication pro-
tocol. The MIDI Port is compatible with MPU-401 UART mode.
The MIDI was originally defined to establish a standard interface between computers and digital musical instruments such
as synthesizers, and has become the de facto standard for this purpose. However, the MIDI is also commonly used for other
purposes, such as communicating with advanced game devices.
The MIDI Port serves as a communication pipe between software and a MIDI device. The software and the MIDI device must
interpret the data they exchange, and act accordingly.
The MIDI Port supports the following two feature types:
Legacy. These include all features supported by MPU-401 UART mode. They can all be operated via the Legacy I/O ad-
dress space of 2 bytes, traditionally allocated for the MIDI Port.
Enhanced. These features extend the capabilities of the MIDI Port. They can only be operated if the MIDI is allocated with
an address space of at least 3 bytes.
The basic system configuration of the MIDI Port consists of the port itself, a single pull-up resistor for the MDRX pin, and a
MIDI compliant device. This system configuration is shown in Figure 17. The purpose of the pull-up resistor is to make sure
that the MIDI Port senses an inactive (high) MIDI receive signal in the absence of a MIDI device.
6.2 FUNCTIONAL DESCRIPTION
The MIDI Port consists of five major functional blocks:
See Figure 18 for a block diagram of the MIDI Port.
Legacy (MPU-401)
Enhanced.
Internal Bus Interface Unit
Port Control and Status Registers
Data Buffers and FIFOs
MIDI Communication Engine
MIDI Signals Routing Control Logic.
MIDI
Port
MIDI Transmit
MIDI Receive
Figure 17. MIDI System Configuration
MDRX Pin
MDTX Pin
96
R
MIDI Transmit
MIDI Receive
Device
MIDI
Device
Game
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