Control State Descriptions
MU9C4320L ATMCAM
Read Highest-Priority
Matching Location
RD[HPM]
Control State:
Mnemonic:
Indirect Read at Address;
Decrement Address Register
RD[AR]
Control State:
Mnemonic:
Binary Op Code: XXX XXX 100 111
Binary Op Code: XXX XXX 000 010
/W: HIGH /AV: HIGH PA:AA: aaa Scope: S
Description: Reads data from the location defined by the
contents of the Address register to the DQ31–0 bus. This
control state provides indirect random access memory
reads. During the Read cycle, the /VB line carries the
Validity Bit value of the addressed location. The contents
of the Address register are decremented.
/W: HIGH /AV: HIGH PA:AA: HPMA Scope: HPD
Description: Reads data from the location defined by the
highest-priority matching location to the DQ31–0 bus. In
the event that the previous Comparison cycle resulted in a
mismatch, the DQ31–0 bus will remain in high
impedance.
Register Read/Write
Control State:
Mnemonic:
Write at Next Free Address
WR[NFA]{MRnnn}
Control State:
Mnemonic:
Write Address Register
WR AR{MRnnn}
Binary Op Code: XXX nnn 000 001
Binary Op Code: XXX nnn 000 100
/W: LOW /AV: HIGH PA:AA: NFA Scope: NFD
Description: Writes data from the DQ31–0 bus to the next
free location in the Memory array. In a vertically cascaded
system, the write will take place in the device whose
/FI=LOW and /FF=HIGH, and at the highest-priority
location whose Validity bit is set HIGH. The validity of
the location is set by the state of the /VB input, /VB =
LOW: Valid, /VB = HIGH: Empty. The write is masked by
the contents of Mask Register nnn. When nnn=000 no
mask is used; when masking is selected, only bits in the
addressed location that correspond to LOW values in the
selected mask register are updated.
/W: LOW /AV: HIGH PA:AA: n/c Scope: AS
Description: Writes data from the DQ31–0 bus to the
Address register. The write is masked by the contents of
Mask Register nnn. When nnn=000 no mask is used; when
masking is selected, only bits in the addressed location
that correspond to LOW values in the selected mask
register are updated.
Control State:
Mnemonic:
Read Address Register
RD AR
Binary Op Code: XXX XXX 000 100
/W: HIGH /AV: HIGH PA:AA: n/c Scope: S
Description: Reads the contents of the Address register to
the DQ31–0 bus.
Control State:
Read Highest-Priority
Matching Location; Increment
Match Address
Control State:
Mnemonic:
No Operation
NOP
Mnemonic:
RD[HPM];INC MA
Binary Op Code: XXX XXX 000 011
Binary Op Code: XXX XXX 000 001
/W: LOW /AV: HIGH PA:AA: n/c Scope: n/a
Description: No operation. The device performs no
operation during the cycle. No existing states change.
/W: HIGH /AV: HIGH PA:AA: HPMA Scope: HPD
Description: Reads data from the location defined by the
highest-priority matching location to the DQ31–0 bus. In
the event that the previous Comparison cycle resulted in a
mismatch, the DQ31–0 bus will remain in high
impedance. The Next Highest-Priority Matching location
is selected and its address appears on the PA3–0:AA11–0
lines.
Control State:
Mnemonic:
Read Next Free Address
RD NFA
Binary Op Code: XXX XXX 000 011
/W: HIGH /AV: HIGH PA:AA: n/c Scope: NFD
Description: Reads the value of the Next Free address on
the DQ11–0 bus. In a vertically cascaded system this will
be in the device whose /FI=LOW and /FF=HIGH, and at
the highest-priority location whose Validity bit is set
HIGH. This value is the address of the location where a
subsequent Write at Next Free Address cycle will be
written. The Page address of the device value is output on
DQ15–12; DQ31–16 are LOW.
Control State:
Write to Highest-Priority
Matching Location
WR[HPM]{MRnnn}
Mnemonic:
Binary Op Code: XXX nnn 000 010
/W: LOW /AV: HIGH PA:AA: HPMA Scope: HPD
Description: Writes data from the DQ31–0 bus to the
highest-priority matching location in the Memory array.
The validity of the location is set by the state of the /VB
input, /VB=LOW: Valid, /VB=HIGH: Empty. The write is
masked by the contents of Mask Register nnn. When
nnn=000 no mask is used; when masking is selected, only
bits in the addressed location that correspond to LOW
values in the selected mask register are updated.
Rev. 3
21