ox16pci958 Oxford Electrical Products, ox16pci958 Datasheet - Page 17

• Manufacturer Part Number: ox16pci958
• Description: Octal Uart With Interface
• Manufacturer: Oxford Electrical Products

OXFORD SEMICONDUCTOR LTD.
Individual bits within the registers are referred
to by the register mnemonic with the bit
number appended. For example, LCR7 refers
to bit 7 of the line control register.
The register accessed when an I/O read or
write is performed depends on the bits 2:0 of
the internal address, the divisor latch access
bit (DLAB, which is LCR7), and the Indexed
Register Select register (IRSR). Registers with
A2:0 from 0 to 7 are accessed through BAR2
or BAR4, and those with A2:0 from 8 to 9 are
accessed through BAR3 or BAR5. See
section 3.1 for details.
The transmitter holding register and receiver
buffer register are used to transfer data for
transmission and received data respectively.
These are eight-bit registers, but the serial
data may be 5, 6, 7 or 8 bits long: data is right-
justified and padded with zeroes on the left.
The UART always receives and transmits bit 0
first. The THR and RBR can be accessed at
the same time as serial data transmission and
reception are taking place, because the
serializer and deserializer are separate from
the data buffers/FIFOs.
DS-0022 Nov 05
UART Status (read only)
Interrupt identification
Line status
Modem status
Chip ID register
Receive FIFO level
Transmit FIFO level
Build & Test
Scratch pad
Inverted scratch pad
Mnem.
IIR
LSR
MSR
CIDR
RFLR
TFLR
Mnem.
SCR
ISCR
External—Free Release
OX16PCI958 DATA SHEET
Page 17