USB to Quad Serial Port Bridge Data Sheet
Oxford Semiconductor, Inc.
Figure 1 shows the Oxford Semiconductor OXUSB954.
Figure 1 OXUSB954 Diagram
Watchdog
Timer
DTR
RTS
DCD
DSR
VP
USB
Interface
VM
Serial
Timer 1
Timer 0
Interface
x4
CTS
RI
16-Bit
Processor
Serial
interface
Engine
Txd
Rxd
16-Bit Address/Data Bus
UART_Txd
UART_Rxd
Debug
UART
CLK
3 Kbytes RAM
Mask ROM
PLL & Clock
Generator
x2
External
Memory
Interface
EEPROM
Serial
Interface
SCL
SDA
Functionality
The OXUSB954 integrated 16-bit processor has direct access to the RAM
buffer, external memory, I/O interfaces, and all control and status
registers. It runs at up to 5 MIPs. It serves as a micro-controller for USB
peripherals, offering additional processing power that allows the design
of intelligent peripherals that can process data prior to passing it to the
host PC. This type of task optimization enhances system efficiency and
improves overall performance, while the masked ROM instruction set
promotes efficient code for algorithm and USB transaction processing.
The processor supports up to 240 software interrupt vectors.
The processor provides the following address modes:
Memory-to-memory
Memory-to register
Register-to-register
Immediate-to-register
Immediate-to-memory
Register, direct, immediate, indirect and indirect-indexed addressing
modes are supported, plus an additional auto-increment mode, in which
a register used as an address pointer is automatically incremented after
each use, making repetitive operations more efficient.
2
External—Free Release
DS-0016 Oct 06
OXFORD [ OXFORD SEMICONDUCTOR ]
