Revision 1.02 – April 12, 2007
S5920 – PCI Product: PCI Configuration Registers
Data Book
The Built-In Self-Test (BIST) Register permits the
implementation of custom, user-specific diagnostics.
This register has four fields shown in Figure 10. Bit 7
defines S5920's support of a built-in self test. When bit
7 is set, writing a 1 to bit 6 produce an interrupt signal
on the Add-On bus. Bit 6 remains set until cleared by a
write operation to this register from the Add-On bus
interface. When bit 6 is reset, it is interpreted as com-
pletion of the self-test and an error is indicated by a
non-zero value for the completion code (bits 3:0).
BUILT-IN SELF-TEST REGISTER (BIST)
Built-in Self-Test Address Offset 0Fh
Register Name:
00h
Power-up value:
Boot-load:
External nvRAM/EPROM offset
04Fh
D7, D5-0 Read Only, D6 as PCI bus
write only
Attribute:
Size:
8 bits
Figure 16. Built-In Self-Test Register
7
X
6
0
5
4
3
0
00
X
Completion Code (RO)
Reserved (RO)
Start BIST (R/WS)
BIST Capable (RO)
Bit
Description
7
BIST Capable. This bit indicates the Add-On device supports a built-in self-test when a 1 is returned. A 0 should
be returned if this self-test feature is not required. This field is read only from the PCI interface.
6
Start BIST. Writing a 1 to this bit indicates that the self-test should start. This bit can only be written if bit 7 is
one. When bit 6 is set, an interrupt is issued to the Add-On interface. Other than through a reset, Bit 6 can only
be cleared by a write to this element from the Add-On bus interface. The PCI bus specification requires that this
bit be cleared within 2 seconds after being set, or the device will be failed. This bit is read/write set (R/WS).
5:4
3:0
Reserved. These bits are reserved and are hardwired to 0.
Completion Code. This field provides a method for detailing a device-specific error. It is considered valid when
the start BIST (bit 6) changes from 1 to 0. An all-zero value for the completion code indicates successful com-
pletion.
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DS1596
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