pc87317vul National Semiconductor Corporation, pc87317vul Datasheet - Page 229

• Manufacturer Part Number: pc87317vul
• Description: Pc87317vul/pc97317vul Superi/o Plug And Play Compatible With Acpi Compliant Controller/extender
• Manufacturer: National Semiconductor Corporation

11.0 X-Bus Data Buffer
The X-Bus Data Buffer (XDB) connects the 8-bit X data bus
to the system data bus via the PC87307VUL data bus. The
XDB is selected by bit 4 of Super/O Chip Configuration 1 reg-
ister (index 21h), as described in Section 2.4.3 "SuperI/O
Configuration 1 Register (SIOC1)" on page 37. This bit is ini-
tialized according to the CFG1 strap pin value.
When XDB is not selected, these pins have alternate func-
tions. See the XDB pin multiplexing Table 1-2 on page 25.
When XDCS is inactive, XD7-0 are not driven or gated to D7-0.
When XDCS is active XD7-0 are linked to D7-0 as follows:
D7-0 values are driven onto XD7-0 pins when XDRD
is inactive.
XD7-0 values are driven onto D7-0 pins when XDRD
is active.
X-Bus Data Buffer
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