LPC47M192-NW Standard Microsystems (SMSC), LPC47M192-NW Datasheet - Page 79

• Manufacturer Part Number: LPC47M192-NW
• Manufacturer: Standard Microsystems (SMSC)

Specifications of LPC47M192-NW

• Lead Free Status / RoHS Status: Compliant

7.7.2 HOST INTERFACE
Overview
The Host Interface includes two contiguous 8-bit run-time registers (the Status/Command Port and the Data Port),
and an interrupt. For illustration purposes, the Host Interface block shown in FIGURE 2 uses standard ISA signaling.
Address decoding and interrupt selection for the Host Interface are determined by device configuration registers (see
Section “MPU-401Configuration Registers”).
I/O Addresses
The Sound Blaster 16 MPU-401 UART mode MIDI interface requires two consecutive I/O addresses with possible
base I/O addresses of 300h and 330h. The default is 330h. The LPC47M192 MPU-401 I/O base address is
programmable on even-byte boundaries throughout the entire I/O address range (see Section “Activate and I/O Base
address”).
Registers (Ports)
The run-time registers in the MPU-401 Host Interface are shown below in Table 33.
7.7.3 MIDI DATA PORT
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”
7.7.4 STATUS PORT
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 35). Status port Bit 6 is MIDI Transmit Busy, Bit 7 is MIDI Receive Buffer Empty. The remaining
bits in the Status port are RESERVED.
7.7.4.1
Bit 7 MIDI Receive Buffer Empty indicates the read state of the MIDI Data port (Table 36). If the MRBE bit is ‘0’, MIDI
Read/Command Acknowledge data is available to the host.
Acknowledge data is NOT available to the host.
SMSC DS – LPC47M192
NAME
TYPE
TYPE
BIT
NAME
REGISTER NAME
MIDI DATA
STATUS
COMMAND
The MIDI Data port is read/write (Table 34). The MIDI Data port is also used to return the command
MIDI DATA/COMMAND-ACKNOWLEDGE REGISTER
Bit 7 – MIDI Receive Buffer Empty
R/W
D7
MPU-401 I/O BASE ADDRESS+1
D7
R
MIDI RX
BUFFER
EMPTY
R/W
D6
D6
R
MIDI TX
BUSY
MPU-401 I/O Base Address
MPU-401 I/O Base Address + 1
MPU-401 I/O Base Address + 1
Table 33 – MPU-401 HOST INTERFACE REGISTERS
R/W
D5
ADDRESS
D5
R
0
MPU-401 I/O BASE ADDRESS
Table 35 - MPU-401 STATUS PORT
DATASHEET
R/W
D4
Table 34 - MIDI Data Port
D4
R
0
Page 79
R/W
D3
D3
R
0
TYPE
R/W
W
R
If the MRBE bit is ‘1’, MIDI Read/Command
R/W
D2
D2
R
0
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.
R/W
D1
D1
R
0
DESCRIPTION
R/W
D0
D0
R
0
DEFAULT
DEFAULT
0x80
n/a
Rev. 03/30/05