DS632 Datasheet, PDF (14/17 Pages) Xilinx, Inc – PLB interface is based on PLB v4.6 specification

XPS Mailbox (v2.00a)
Table 18: XPS Mailbox RIT Register Bit Definitions
Bit(s)
Name
Core
Access
Reset
Value
Log2(C_MAILB
OX_DEPTH)
RIT
Read/Write
0
Description
Lower Log2(C_MAILBOX_DEPTH) bits used,
right justified to bit 31
XPS Mailbox Interrupt Status Register (IS)
The XPS Mailbox Interrupt Status Register contains the current interrupt status for this interface. There
are three types of interrupts that can be generated. Mailbox Error interrupt are generated when any of
the bits in the ERROR register is set. The other two interrupts are FIFO related: RTI is generated for a
rising edge on the RTA bit in the STATUS register and STI that is generated for a rising edge on the STA
STATUS register bit. RTI and STI are used to indicate that it is time to read from or write to the FIFOs
to avoid any stalls in the data flow. Bit assignment in the IS register is described in Table 20.
Table 19: IS Register
0
Reserved
ERR RTI STI
28
29
30
31
Table 20: XPS Mailbox IS Register Bit Definitions
Bit(s)
Name
Core
Access
Reset
Value
Description
0 - 28
Reserved
Reserved for future use
Mailbox Error Interrupt Status for this interface.
Values for read:
’0’ = No interrupt event has occurred.
29
ERR
Read/Write
’0’
’1’ = A Mailbox error has occurred.
Values for write:
’0’ = No change
’1’ = Acknowledge and clear the interrupt if it is active
Mailbox Receive Threshold Interrupt pending status for
this interface.
Values for read:
30
RTI
Read/Write
’0’
’0’ = No interrupt event has occurred.
’1’ = Data level in the receive FIFO has caused a RTI.
Values for write:
’0’ = No change
’1’ = Acknowledge and clear the interrupt if it is active
Mailbox Send Threshold Interrupt penging status for this
interface.
Values for read:
31
STI
Read/Write
’0’
’0’ = No interrupt event has occurred.
’1’ = Data level in the send FIFO has caused a STI.
Values for write:
’0’ = No change
’1’ = Acknowledge and clear the interrupt if it is active
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DS632 June 24, 2009
Product Specification