CY7C43646AV 데이터 시트보기 (PDF) - Cypress Semiconductor
부품명
상세내역
일치하는 목록
CY7C43646AV Datasheet PDF : 40 Pages
| |||
CY7C43646AV
CY7C43666AV
CY7C43686AV
To load a FIFO’s Almost Empty flag and Almost Full flag offset
register with one of the three preset values listed in Table 1,
the Serial Program Mode (SPM) and at least one of the flag-
select inputs must be HIGH during the LOW-to-HIGH
transition of its Master Reset input (MRS1 and MRS2). For
example, to load the preset value of 64 into X1 and Y1, SPM,
FS0 and FS1 must be HIGH when FIFO1 reset (MRS1) returns
HIGH. Flag-offset registers associated with FIFO2 are loaded
with one of the preset values in the same way with Master
Reset (MRS2). When using one of the preset values for the
flag offsets, the FIFOs can be reset simultaneously or at
different times.
To program the X1, X2, Y1, and Y2 registers in parallel from
Port A, perform a Master Reset on both FIFOs simultaneously
with SPM HIGH and FS0 and FS1 LOW during the LOW-to-
HIGH transition of MRS1 and MRS2. After this reset is
complete, the first four Writes do not store data in RAM but
load the offset registers in the order Y1, X1, Y2, X2. The Port
A data inputs used by the offset registers are (A0–9), (A0–11),
or (A0–13), for the CY7C436X6AV, respectively. The highest
numbered input is used as the most significant bit of the binary
number in each case. Valid programming values for the
registers range from 0 to 1023 for the CY7C43646AV; 0 to
4095 for the CY7C43666AV; 0 to 16383 for the CY7C43686AV
(see note 61). After all the offset registers are programmed
from Port A, the Port C Full/Input Ready (FFC/IRC) is set HIGH
and both FIFOs begin normal operation.
To program the X1, X2, Y1, and Y2 registers serially, initiate a
Master Reset with SPM LOW, FS0/SD LOW, and FS1/SEN
HIGH during the LOW-to-HIGH transition of MRS1 and MRS2.
After this reset is complete, the X and Y register values are
loaded bit-wise through the FS0/SD input on each LOW-to-
HIGH transition of CLKA that the FS1/SEN input is LOW. 40-,
48-, or 56-bit Writes are needed to complete the programming
for the CY7C436X6AV, respectively. The four registers are
written in the order Y1, X1, Y2, and, finally, X2. The first-bit
Write stores the most significant bit of the Y1 register and the
last-bit Write stores the least significant bit of the X2 register.
When the option to program the offset registers serially is
chosen, the Port A Full/Input Ready (FFA/IRA) flag remains
LOW until all register bits are written. FFA/IRA is set HIGH by
the LOW-to-HIGH transition of CLKA after the last bit is loaded
to allow normal FIFO operation. The Port C Full/Input ready
(FFC/IRC) flag also remains LOW throughout the serial
programming process, until all register bits are written.
FFC/IRC is set HIGH by the LOW-to-HIGH transition of CLKC
after the last bit is loaded to allow normal FIFO2 operation.
SPM, FS0/SD, and FS1/SEN function the same way in both
CY Standard and FWFT modes.
FIFO Write/Read Operation
The state of the Port A data (A0–35) lines is controlled by Port
A Chip Select (CSA) and Port A Write/Read Select (W/RA).
The A0–35 lines are in the high-impedance state when either
CSA or W/RA is HIGH. The A0–35 lines are active outputs
when both CSA and W/RA are LOW.
Data is loaded into FIFO1 from the A0–35 inputs on a LOW-to-
HIGH transition of CLKA when CSA is LOW, W/RA is HIGH,
ENA is HIGH, MBA is LOW, and FFA/IRA is HIGH. Data is read
from FIFO2 to the A0–35 outputs by a LOW-to-HIGH transition
of CLKA when CSA is LOW, W/RA is LOW, ENA is HIGH, MBA
is LOW, and EFA/ORA is HIGH (see Table 2). FIFO Reads and
Writes on Port A are independent of any concurrent Port B
operation.
The state of the Port B data (B0–17) lines is controlled by the
Port B Chip Select (CSB) and Port B Read select (RENB). The
B0–17 lines are in the high-impedance state when either CSB
is HIGH or RENB is LOW. The B0–17 lines are active outputs
when CSB is LOW and RENB is HIGH.
Data is loaded into FIFO2 from the C0–17 inputs on a LOW-to-
HIGH transition of CLKC when WENC is HIGH, MBC is LOW,
and FFC/IRC is HIGH (see Table 4). Data is read from FIFO1
to the B0–17 outputs by a LOW-to-HIGH transition of CLKB
when CSB is LOW, RENB is HIGH, MBB is LOW, and
EFB/ORB is HIGH (see Table 3). FIFO Reads on Port B and
Writes to Port C are independent of any concurrent Port A
operation.
The set-up and hold time constraints to the port clocks for the
port Chip Selects and Write/Read selects are only for enabling
Write and Read operations and are not related to high-
impedance control of the data outputs. If a port enable is LOW
during a clock cycle, the port’s Chip Select and Write/Read
select may change states during the set-up and hold time
window of the cycle.
When operating the FIFO in FWFT Mode with the Output
Ready flag LOW, the next word written is automatically sent to
the FIFO’s output register by the LOW-to-HIGH transition of
the port clock that sets the Output Ready flag HIGH, data
residing in the FIFO’s memory array is clocked to the output
register only when a Read is selected using the port’s Chip
Select, Write/Read select, Enable, and Mailbox select.
When operating the FIFO in CY Standard mode, regardless of
whether the Empty Flag is LOW or HIGH, data residing in the
FIFO’s memory array is clocked to the output register only
when a Read is selected using the port’s Chip Select,
Write/Read select, Enable, and Mailbox select.
Synchronized FIFO Flags
Each FIFO is synchronized to its port clock through at least two
flip-flop stages. This is done to improve flag-signal reliability by
reducing the probability of the metastable events when CLKA,
CLKB, and CLKC operate asynchronously to one another.
EFA/ORA, AEA, FFA/IRA, and AFA are synchronized to
CLKA. EFB/ORB and AEB are synchronized to CLKB.
FFC/IRC and AFC are synchronized to CLKC. Table 5 and
Table 6 show the relationship of each port flag to FIFO1 and
FIFO2.
Empty/Output Ready Flags (EFA/ORA, EFB/ORB)
These are dual-purpose flags. In the FWFT Mode, the Output
Ready (ORA, ORB) function is selected. When the Output
Ready flag is HIGH, new data is present in the FIFO output
register. When the Output Ready flag is LOW, the previous
data word remains in the FIFO output register, and any FIFO
Reads are ignored.
In the CY Standard mode, the Empty Flag (EFA, EFB) function
is selected. When the Empty Flag is HIGH, data is available in
the FIFO’s RAM memory for reading to the output register.
When Empty Flag is LOW, the previous data word remains in
the FIFO output register, and any FIFO Reads are ignored.
The Empty/Output ready flag of a FIFO is synchronized to the
port clock that reads data from its array. For both the FWFT
and CY Standard modes, the FIFO Read pointer is incre-
Document #: 38-06026 Rev. *C
Page 8 of 40
Share Link: 