LPC47M140-NC SMSC [SMSC Corporation], LPC47M140-NC Datasheet - Page 77

• Manufacturer Part Number: LPC47M140-NC
• Description: 128 PIN ENGANCED SUPER I/O CONTROLLER WITH AN LPC INTERFACE AND USB HUB
• Manufacturer: SMSC [SMSC Corporation]

cleared before the command acknowledge byte is placed in the MIDI Data port read buffer.
6.8.6
Overview
The UART is used to transmit and receive MIDI protocol data from the MIDI Data port in the Host Interface (see
Section “Host Interface”).
The MIDI protocol requires 31.25k Baud (±1%) and 10 bits total per frame: 1 start bit, 8 data bits, no parity, and 1
stop bit. For example, there are 320 microseconds per serial MIDI data byte. MIDI data is transferred LSB first
(Figure 7).
The UART is configured in full-duplex mode for the MPU-401 MIDI Interface, with 16-byte send/receive FIFOs.
Note
6.8.7
The LPC47M14x configuration registers are in Logical Device B (see “Configuration” section). The configuration
registers contain the MPU-401 Activate, Base Address and Interrupt select. The defaults for the Base Address and
Interrupt Select configuration registers match the MPU-401 factory defaults.
Activate and I/O Base Address
When the Activate bit D0 is ‘0’, the MPU-401 I/O base address decoder is disabled, the IRQ is always deasserted,
and the MPU-401 hardware is in a minimum power-consumption state. When the Activate bit is ‘1’, the MPU-401 I/O
base address decoder and the IRQ are enabled, and the MPU-401 hardware is fully powered.
Register 0x60 is the MPU-401 I/O Base Address High Byte, register 0x61 is the MPU-401 I/O Base Address Low
Byte. The MPU-401 I/O base address is programmable on even-byte boundaries. The valid MPU-401 I/O base
address range is 0x0100 – 0x0FFE. See Section “Host Interface”.
SMSC DS – LPC47M14X
MIDI RX CLOCK
1
:
MIDI UART
MIDI RX CLOCK is the MIDI bit clock. The MIDI bit clock period is 32µs.
MPU-401 Configuration Registers
MIDI_IN
1
FIGURE 5 - MIDI DATA BYTE EXAMPLE
Page 77
MIDI RX DATA BYTE (01H)
Rev. 03/19/2001