S5935QF Applied Micro Circuits Corporation, S5935QF Datasheet - Page 136

• Manufacturer Part Number: S5935QF
• Manufacturer: Applied Micro Circuits Corporation

Specifications of S5935QF

• Package Type: PQFP
• Rad Hardened: No
• Lead Free Status / Rohs Status: Not Compliant

S5935 – PCI Product
64-Bit Endian Conversion
Because the S5935 interfaces to a 32-bit PCI bus, special operation is required to handle 64-bit data endian con-
version. Figure 2c shows 64-bit endian conversion. The S5935 must know whether the lower 32-bits enter the
FIFO first or the upper 32-bits enter the FIFO first. INTCSR D31:30 identify which method is used by the applica-
tion. These bits toggle after each 32-bit operation to indicate if half or all of a 64-bit data operation has been
completed. The initial state of these bits establishes the loading and emptying order for 64-bit data during
operation.
Figure 2c. 64-bit Endian Conversion
136
DS1527
BYTES 3-0 FIRST
BYTES 7-4 FIRST
BYTES 3-0 FIRST
BYTES 7-4 FIRST
READ ORDER:
LOAD ORDER:
SEE TEXT
SEE TEXT
OR,
OR
BYTE 7
BYTE 7
BYTE 6
BYTE 6
BYTE 5
BYTE 5
BYTE 4
BYTE 4
D 31-24
D 31-24
SLR
BYTE 3
BYTE 3
SOURCE
D 23-16
D 23-16
SLR
BYTE 2
DESTINATION
BYTE 2
Revision 1.02 – June 27, 2006
AMCC Confidential and Proprietary
D 15-8
D 15-8
SLR
BYTE 1
BYTE 1
D 7-0
SLR
D 7-0
BYTE 0
BYTE 0
Data Book