PCI Local Bus
http://www.motorola.com/computer/literature 1-23
1
Dual TL16C550 UARTs
The MVME5100 implementation of the Dual TL16C550 UARTs are fully
compliant with the PowerPlus II Programming Model for UART
Registers. The following tables reflect th is model.
The MVME5100 uses UART-1 and UART-2 for asynchronous serial
debug ports (four are allowed by the PowerPlus II Programming Model).
The first UART (UART-1) is addressed at External Register Set Address
Offset $8000 (FEF8 8000). The second (UART-2) is addressed at offset
$8200 (FEF8 8200). The UART 8-bit data port (RD0-RD7) is connected
to the most significant bits of the 64-bit External Register Set. The UART
port addressing occurs on 16-byte address boundaries, and are backward
compatible with the PPMC750.
Table 1-10. 16550 Access Registers
Required or
Optional External Register
Set Address Offset Function
UART-1 Registers 8000 Receiver Buffer (Read), Transmitter Holding (Write)
8010 Interrupt Enab le
8020 Interrupt Identification (Read), FIFO Control (Write)
8030 Line Control
8040 MODEM Contro l
8050 Line Status
8060 MODEM Status
8070 Scratch
UART-2 Registers 8200 Receiver Buffer (Read), Transmitter Holding (Write)
8210 Interrupt Enab le
8220 Interrupt Identification (Read), FIFI Control (Write)
8230 Line Control
8240 MODEM Contro l
8250 Line Status
8260 MODEM Status
8270 Scratch