CY7C64713 CYPRESS [Cypress Semiconductor], CY7C64713 Datasheet - Page 43

• Manufacturer Part Number: CY7C64713
• Manufacturer: CYPRESS [Cypress Semiconductor]

10.16.2 Single and Burst Synchronous Write
The Figure 10-18 shows the timing relationship of the SLAVE
FIFO signals during a synchronous write using IFCLK as the
synchronizing clock. The diagram illustrates a single write
followed by burst write of 3 bytes and committing all 4 bytes as
a short packet using the PKTEND pin.
The same sequence of events are also shown for a burst write
and are marked with the time indicators of T=0 through 5.
Note: For the burst mode, SLWR and SLCS are left asserted
for the entire duration of writing all the required data values. In
this burst write mode, once the SLWR is asserted, the data on
the FIFO data bus is written to the FIFO on every rising edge
Document #: 38-08039 Rev. *B
PKTEND
FLAGS
FIFOADR
• At t = 0 the FIFO address is stable and the signal SLCS is
• At t = 1, the external master/peripheral must outputs the
• At t = 2, SLWR is asserted. The SLWR must meet the setup
• While the SLWR is asserted, data is written to the FIFO and
IFCLK
SLWR
SLCS
DATA
asserted. (SLCS may be tied low in some applications)
Note: t
is running at 48 MHz, the FIFO address setup time is more
than one IFCLK cycle.
data value onto the data bus with a minimum set up time of
t
time of t
rising edge of IFCLK) and maintain a minimum hold time of
t
SLWR signal). If SLCS signal is used, it must be asserted
with SLWR or before SLWR is asserted. (i.e. the SLCS and
SLWR signals must both be asserted to start a valid write
condition).
on the rising edge of the IFCLK, the FIFO pointer is incre-
mented. The FIFO flag will also be updated after a delay of
t
SFD
WRH
XFLG
before the rising edge of IFCLK.
(time from the IFCLK edge to the de-assertion of the
from the rising edge of the clock.
SFA
SWR
has a minimum of 25 ns. This means when IFCLK
(time from asserting the SLWR signal to the
t=0
Figure 10-18. Slave FIFO Synchronous Write Sequence and Timing Diagram
t
SFA
t=1
t=2
t
t
SFD
SWR
t
N
IFCLK
t=3
t
FDH
t
WRH
t
XFLG
t
FAH
T=0
t
SFA
of IFCLK. The FIFO pointer is updated on each rising edge of
IFCLK. In Figure 10-18, once the four bytes are written to the
FIFO, SLWR is de-asserted. The short 4-byte packet can be
committed to the host by asserting the PKTEND signal.
There is no specific timing requirement that needs to be met
for asserting PKTEND signal with regards to asserting the
SLWR signal. PKTEND can be asserted with the last data
value or thereafter. The only consideration is the setup time
t
Figure 10-18, the number of data values committed includes
the last value written to the FIFO. In this example, both the
data value and the PKTEND signal are clocked on the same
rising edge of IFCLK. PKTEND can be asserted in subsequent
clock cycles. The FIFOADDR lines should be held constant
during the PKTEND assertion.
Although there are no specific timing requirement for asserting
PKTEND, there is a specific corner case condition that needs
attention while using the PKTEND to commit a one byte/word
packet. Additional timing requirements exists when the FIFO
is configured to operate in auto mode and it is desired to send
two packets: a full packet (full defined as the number of bytes
in the FIFO meeting the level set in AUTOINLEN register)
committed automatically followed by a short one byte/word
packet committed manually using the PKTEND pin. In this
case, the external master must make sure to assert the
PKTEND pin atleast one clock cycle after the rising edge that
caused the last byte/word to be clocked into the previous auto
committed packet ( the packet with the number of bytes equal
to what is set in the AUTOINLEN register). Refer to section 10-
10 for further details on this timing.
SPE
T=1
T=2
and the hold time t
>= t
t
SFD
SWR
N+1
t
FDH
T=3
t
SFD
N+2
PEH
t
FDH
T=4
must be met. In the scenario of
t
SFD
t
N+3
SPE
[17]
CY7C64713/14
t
>= t
t
XFLG
FDH
T=5
t
WRH
PEH
t
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