S5935QF Applied Micro Circuits Corporation, S5935QF Datasheet - Page 103

• 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
Read accesses from the S5935 operation registers
(S5935 as a target) are shown in Figure 2. The S5935
conditionally asserts STOP# in clock period 3 if the ini-
tiator keeps FRAME# asserted during clock period 2
with IRDY# asserted (indicating a burst is being
attempted). Wait states may be added by the initiator
by not asserting the signal IRDY# during clock 3 and
beyond. If FRAME# remains asserted, but IRDY# is
not asserted, the initiator is just adding wait states, not
necessarily attempting a burst.
There is only one condition where accesses to S5935
operation registers do not return TRDY# but do assert
STOP#. This is called a target-initiated termination or
Figure 47. Single Data Phase PCI Bus Read of S5935 Registers (S5935 as Target)
Figure 48. Burst PCI Bus Read Attempt to S5935 Registers (S5935 as Target)
AMCC Confidential and Proprietary
PCI CLOCK
FRAME #
AD [31:0]
C/BE [3:0]#
IRDY#
TRDY#
DEVSEL#
STOP#
FRAME #
AD [31:0]
C/BE [3:0]#
IRDY#
TRDY#
DEVSEL#
STOP#
(T)
(T)
(T)
(I)
(I)
(I)
(I)
(I)
(T)
(T)
(T)
(I)
1
BUS COMMAND
ADDRESS
BUS COMMAND
(I)
1
ADDRESS
(I)
2
2
BYTE ENABLES (1)
BYTE ENABLES
3
target disconnect and occurs when a read attempt is
made to an empty S5935 FIFO. The assertion of
STOP# without the assertion of TRDY# indicates that
the initiator should retry the operation later.
When burst read transfers are attempted to the S5935
operation registers, STOP# is asserted during the first
data transfer to indicate to the initiator that no further
transfers (data phases) are possible. This is a target
initiated termination where the target disconnects after
the first data transfer. Figure 3 shows the signal rela-
tionships during a burst read attempt to the S5935
operation registers.
DATA
(T)
3
DATA
(T)
45
BE (2)
45
(I) = DRIVEN BY INITIATOR
(T) = DRIVEN BY TARGET
Revision 1.02 – June 27, 2006
(I) = DRIVEN BY INITIATOR
(T) = DRIVEN BY TARGET
Data Book
DS1527
103