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参数资料
型号： M7020R-050ZA1T
厂商： 意法半导体
英文描述： CAP TANT 22UF 10V 20% POLY SMD
中文描述： 32K的× 68位进入网络搜索引擎
文件页数： 126/150页
文件大小： 996K
代理商： M7020R-050ZA1T
M7020R
126/150
SRAM ADDRESSING
Table 50, page 127 describes the commands used
to generate addresses on the SRAM Address Bus.
The index [14:0] field contains the address of a 68-
bit entry that results in a hit in 68-bit-configured
quadrant. It is the address of the 68-bit entry that
lies at the 136-bit page, and the 272-bit page
boundaries in 136-bit- and 272-bit-configured
quadrants, respectively.
REGISTERS, page 21 of this specification, de-
scribes the NFA and SSR Registers. ADR[14:0]
contains the address supplied on the DQ Bus dur-
ing PIO access to the M7020R. Command Bits 8
and 7 {CMD[8:7]} are passed from the command
to the SRAM Address Bus (see COMMAND
CODES AND PARAMETERS, page 29 for more
information). ID[4:0] is the ID of the device driving
the SRAM Bus (see Figure 3, page 10 and Table
2, page 9 for more information).
SRAM PIO Access
SRAM READ enables READ access to off-chip
SRAM that contains associative data. The latency
from the issuance of the READ Instruction to the
address appearing on the SRAM Bus is the same
as the latency of the SEARCH Instruction and will
depend on the TLSZ value parameter pro-
grammed in the device Configuration Register.
The latency of the ACK from the READ Instruction
is the same as the latency of the SEARCH Instruc-
tion to the SRAM address plus the HLAT pro-
grammed in the Configuration Register.
Note:
SRAM READ is a blocking operation – no
new instruction can begin until the ACK is returned
by the selected device performing the access.
SRAM WRITE enables WRITE access to the off-
chip SRAM containing associative data. The laten-
cy from the second cycle of the WRITE Instruction
to the address appearing on the SRAM Bus is the
same as the latency of the SEARCH Instruction
and will depend on the TLSZ value parameter pro-
grammed in the device Configuration Register.
Note:
SRAM WRITE is a pipelined operation –
new instruction can begin right after the previous
command has ended.
SRAM READ with a Table of One Device
SRAM READ enables READ access to the off-
chip SRAM containing associative data. The laten-
cy from the issuance of the READ Instruction to
the address appearing on the SRAM Bus is the
same as the latency of the SEARCH Instruction
and will depend on the TLSZ value parameter pro-
grammed in the device configuration register. The
latency of the ACK from the READ Instruction is
the same as the latency of the SEARCH Instruc-
tion to the SRAM address plus the HLAT pro-
grammed in the configuration register.
The following explains the SRAM READ operation
in a table with only one device that has the follow-
ing parameters: TLSZ = 00, HLAT = 000, LRAM =
1, and LDEV = 1. Figure 93, page 127 shows the
associated timing diagram.
For the following description, the selected device
refers to the only device in the table because it is
the only device to be accessed.
The sequence of the operation is as follows:
–
Cycle 1A:
The host ASIC applies the READ In-
struction on the CMD[1:0], using CMDV = 1.
The DQ Bus supplies the address with
DQ[20:19] set to '10' to select the SRAM ad-
dress. The host ASIC selects the device for
which the ID[4:0] matches the DQ[25:21] lines.
During this cycle, the host ASIC also supplies
SADR[21:20] on CMD[8:7] in this cycle.
–
Cycle 1B:
The host ASIC continues to apply the
READ Instruction on the CMD[1:0] using
CMDV = 1. The DQ Bus supplies the address
with DQ[20:19] set to '10' to select the SRAM
address.
–
Cycle 2:
The host ASIC floats DQ[67:0] to a 3-
state condition.
–
Cycle 3:
The host ASIC keeps DQ[67:0] in a 3-
state condition.
–
Cycle 4:
The selected device starts to drive
DQ[67:0] and drives ACK from High-Z to low.
–
Cycle 5:
The selected device drives the READ
address on SADR[21:0]; it also drives ACK high,
CE_L low, and ALE_L low.
–
Cycle 6:
The selected device drives CE_L high,
ALE_L high, the SADR Bus, and the DQ Bus in
a 3-state condition; it drives ACK low.
At the end of Cycle 6, the selected device floats
ACK in a 3-state condition, and a new command
can begin.
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M702-230642 功能描述:火线接头 IEEE 1394 SMT 6P HORIZONTAL RoHS:否 制造商:Molex 产品:IEEE 1394 Firewire Connectors 标准:IEEE 1394 位置/触点数量:6 节距:2 mm 触点电镀:Unplated 触点材料:Phosphor Bronze 型式:Female 电流额定值:0.5 A 安装风格:Through Hole 端接类型:Solder Tab 连接器类型:Firewire Receptacle
M7023 制造商:Tamura Corporation of America 功能描述:
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