OXCFU950_07 Datasheet, PDF (62/74 Pages) Oxford Semiconductor – USB/UART multi-function 16-bit PC Card device

OXFORD SEMICONDUCTOR, INC.
OXCFU950 DATA SHEET
9 MULTI PURPOSE I/O (MIO) AND USB POWER MANAGEMENT MODULE
The OXCFU950 supports four multi-purpose I/Os (MIOs) for general applications which are fully configurable/controllable by
software. Such applications may be used to control external devices via a serial interface, or act as a status monitor of external
circuits, for example.
The MIO pins can be configured as inputs or outputs, and can cause a general purpose interrupt to be generated (individually
generated for each MIO pin). In addition, in input mode, the active state can be set to logic '1' or logic '0' for additional flexibility.
Refer to the Multi-purpose I/O Configuration description (offset 0x11) and MIO interrupt Enable Register description (offset
0x13) for a description of the MIO pins configuration. See section 6.5 for further details.
In addition to the normal MIO operation, MIO[3:2] can be configured to be used as power management pins, with the use of an
external circuit, to provide USB bus power generation (VBUS) and over-current detection as described in the USB Specification.
Refer to Soft USB Reset and Clock Enable Register (offset 0x17) in section 6.5 for further details.
10 INTERNAL EEPROM SPECIFICATION
The OXCFU950 can be configured using its on-board EEPROM. If the EEPROM does not contain a valid image, the device
remains in its default configuration after reset. Although this may be adequate for some purposes, normal functional operation
requires at least a partial image in the EEPROM.
The EEPROM also allows accesses to the integrated UART and USB host controller, which can be useful for default setups.
The OXCFU950 device includes 512 bytes of internal EEPROM. This allows the device to be configured in the following ways:
1) The CIS can be modified to allow customers to differentiate their products.
2) The registers in I/O space can be written to allow the UART function to be setup in a specific way after a power on, hard or
soft reset.
3) The registers in I/O space can be written to allow the USB function to be setup in a specific way after a power on, hard or
soft reset.
A zone type system is used to tell the device which areas of the device are being programmed. If only one area is being
programmed by the EEPROM, the programming time is reduced by only enabling that particular zone to be downloaded
(encoded in header in EEPROM).
The EEPROM download occurs at three possible times during the PC Card operation:
• Following a power-up of card (after insertion of the card into a socket)
• Following a hard reset, from the RESET pin on the PC Card / CF interface.
• After a soft reset (either USB or UART) a partial reset of the card should take place as follows:
o Following a soft reset (via the UART COR soft reset bit) the UART FCR is reset, as is the UART. The UART
register access zone should then be executed, if present.
o Following a soft reset of the UART (via the LCR) the UART is reset, and the UART register access zone should
then be executed, if present. The UART FCR is not reset.
o Following a soft reset (via the USB COR soft reset bit) the USB FCR is reset, as is the USB host controller. The
USB register access zone should then be executed, if present.
o Following a soft reset of the USB (via the LCR) the USB host controller is reset, and the USB register access zone
should then be executed, if present. The USB FCR is not reset.
When one of these conditions occurs, the EEPROM controller detects whether a valid image is present on the EEPROM. If no
valid image is present, the download is not performed and the default values (for attribute tuple data, etc) are selected.
DS-0023 February 2007
External—Free Release
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