OXCB950 Datasheet, PDF (55/68 Pages) List of Unclassifed Manufacturers – Integrated High Performance UART Cardbus / PCI interface

OXFORD SEMICONDUCTOR LTD.
8.1.6 Zone5: Function Access
Zone 5 allows the UART to be pre-configured, prior to any
cardbus/PCI accesses. This is very useful when the UART
needs to run with (typically generic) device drivers and
these drivers are not capable of utilising the enhanced
features/modes of the UART (eg 950 mode) that are
required for high performance. By using function access,
the UART registers can be accessed (setup) via the
eeprom to customize the UART features before control is
handed to the device drivers.
OXCB950
Each 8-bit (function) access is equivalent to accessing the
UART function through I/O BAR 0, with the exception that a
function read access does not return any data (it is
discarded). The UART function behaves as though these
function accesses via the eeprom were corresponding
cardbus/pci accesses.
Each entry for zone 5 comprises 2 16 bit words. The format
is as shown in Table 14.
Word
Word
1^st WORD of FUNCTION ACCESS PAIR
Bits
15
14:12
11
10:8
7:0
Description
‘1’ - another WORD to follow
BAR number to access
000 for BAR 0 (UART IO BAR)
Others values are reserved
‘0’ : Read access required(data will be discarded)
‘1’ : Write access required
Reserved – write 0’s
I/O address to access
This is the address that needs to be written/read and is
the offset address from the specified BAR. E.g to access
SPR register of UART, address is 00000111 (7dec).
2^nd WORD of FUNCTION ACCESS PAIR
Bits Description
15
‘1’ – another function access WORD pair to follow.
‘0’ – no more function access word pairs. End EEPROM
program.
14:8 Reserved – write 0’s
7:0
Data to be written to specified address.
Field is unused for function access READS (set to 0’s for
reads)
Data Sheet Revision 1.1
Page 55