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MU9C1480A/L Draft
Rev. 3.0 Draft
13
NOTES:
1.
Exceptions are:
A) A write to the Device Select register is always active in all devices;
B) A write to the Page Address register is active in the device with /FI LOW and /FF HIGH; and
C) The Set Full Flag (SFF) instruction is active in the device with /FI LOW and /FF HIGH.
If /MF is disabled in the Control register, Internal /MA is forced HIGH preventing a Case 6 response.
This is NO for a MOV instruction involving Memory at Next Free address if /FI is HIGH or the device is full.
This is NO if the Persistent Destination is Memory at Next Free address and /FI is HIGH or the device is full.
For a Command read following a TCO NF instruction, this is YES if the device contains the first empty location in a daisy chain
(i.e., /FI LOW and /FF HIGH) and NO if it does not.
This is NO for a MOV or VBC instruction involving Memory at Highest-Priority match.
This is NO if the Persistent Destination is Memory at Highest-Priority match.
2.
3.
4.
5.
6.
7.
Table 5a: Standard Mode Device Select Response
Case
1
2
3
4
5
6
2
Internal
/EC(int)
1
1
1
0
0
0
Internal
/MA (int)
X
X
X
X
1
0
External
/MI
X
X
X
0
1
1
Device Select
Register
DS=FFFFH
DS=PA
DS
≠
FFFFH and
DS
≠
PA
X
X
X
Command
Write
1
YES
3
YES
3
NO
NO
NO
YES
3
Data Write
YES
4
YES
4
NO
NO
NO
YES
4
Command
Read
NO
YES
NO
NO
5
NO
5
YES
5
Data Read
NO
YES
NO
NO
NO
YES
Table 5b: Enhanced Mode Device Select Response
Case
1
2
3
4
5
6
2
Internal
/EC(int)
1
1
1
0
0
0
Internal
/MA (int)
X
X
X
0
1
0
External
/MI
X
X
X
0
X
1
Device select
Register
DS = FFFFH
DS = PA
DS
≠
FFFFH
and DS
≠
PA
X
X
X
Command
Write
1
YES
3
YES
3
NO
YES
3,6
YES
3,6
YES
3
Data Write
YES
4
YES
4
NO
YES
4,7
YES
4,7
YES
4
Command
Read
NO
YES
NO
NO
5
NO
5
YES
5
Data Read
NO
YES
NO
NO
NO
YES
OPERATIONAL CHARACTERISTICS Continued
Match Flag Cascading
The Match Flag daisy chain cascading is used for three
purposes: first, to allow operations on Highest-Priority
Match addresses to be issued globally over the whole
string; second, to provide a system wide match flag; third,
to lock out all devices except the one with the
Highest-Priority match for instructions such as Status reads
after a match. The Match flag logic causes only the
highest-priority device to operate on its Highest-Priority
Match location while devices with lower-priority matches
ignore Highest-Priority Match operations. The lock-out
feature is enabled by the match flag cascading and the use
of the /EC control signal, as shown in Tables 5a and 5b.
Figure 6: /EC (Int) Timing Diagram
/E
/EC
/EC (INT)
/MF