LPC47M140-NC SMSC [SMSC Corporation], LPC47M140-NC Datasheet - Page 74

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

The run-time registers in the MPU-401 Host Interface are shown below in Table 34.
6.8.3
The MIDI Data port exchanges MIDI transmit and MIDI receive data between the MPU-401 UART interface and the
host.
acknowledge byte ‘FEh’ following host writes to the COMMAND port.
The MIDI Data port is full-duplex; i.e., the transmit and receive buffers can be used simultaneously.
An interrupt is generated when either MIDI receive data or a command acknowledge is available to the host in the
MIDI Data register. See Section “Bit 7 – MIDI Receive Buffer Empty” and “Interrupt”
6.8.4
The Status port is used to indicate the state of the transmit and receive buffers in the MIDI Data port. The Status port
is read-only (Table 36). Status port Bit 6 is MIDI Transmit Busy, Bit 7 is MIDI Receive Buffer Empty. The remaining
bits in the Status port are RESERVED.
Bit 7 – MIDI Receive Buffer Empty
Bit 7 MIDI Receive Buffer Empty indicates the read state of the MIDI Data port (Table 37). If the MRBE bit is ‘0’, MIDI
Read/Command Acknowledge data is available to the host.
Acknowledge data is NOT available to the host.
The MPU-401 Interrupt output is active ‘1’ when the MIDI Receive Buffer Empty bit is ‘0’. The MPU-401 Interrupt
output is inactive ‘0’ when the MIDI Receive Buffer Empty bit is ‘1’. See Section “Interrupt” for more information.
SMSC DS – LPC47M14X
TYPE
NAME
TYPE
BIT
NAME
REGISTER NAME
MIDI DATA
STATUS
COMMAND
The MIDI Data port is read/write (Table 35). The MIDI Data port is also used to return the command
MIDI Data Port
Status Port
D7
R/W
MIDI DATA/COMMAND-ACKNOWLEDGE REGISTER
D7
R
MIDI RX
BUFFE
R
EMPTY
R
D6
R/W
D6
MIDI TX
BUSY
MPU-401 I/O Base Address
MPU-401 I/O Base Address + 1
MPU-401 I/O Base Address + 1
Table 34 – MPU-401 Host Interface Registers
D5
R/W
D5
R
ADDRESS
0
MPU-401 I/O BASE ADDRESS+1
Table 36 – MPU-401 Status Port
MPU-401 I/O BASE ADDRESS
Table 35 – MIDI Data Port
D4
R/W
D4
R
0
Page 74
D3
R/W
D3
R
0
R/W
R
W
TYPE
If the MRBE bit is ‘1’, MIDI Read/Command
D2
R/W
D2
R
Used for MIDI transmit data, MIDI
receive data, and MPU-401 command
acknowledge.
Used to indicate the send/receive status
of the MIDI Data port.
Used for MPU-401 Commands.
0
D1
R/W
D1
R
0
DESCRIPTION
D0
R/W
D0
R
0
DEFAULT
n/a
DEFAULT
0x80
Rev. 03/19/2001