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NAME
PTEST -- TESTs a logic address (PRIVILEGED)
SYNOPSIS
PTESTR <FC>,<ea>,#<level>
PTESTR <FC>,<ea>,#<level>,An
PTESTW <FC>,<ea>,#<level>
PTESTW <FC>,<ea>,#<level>,An
No size specs.
FUNCTION
This instruction examines the ATC, if level is equal to zero,
a research in the translation tables is made, if level is different
of zero (1 to 7), then sets MMUSR bits.
This instruction can also store, in an address register An, physical
address encountred to last level of its research.
PTESTR or PTESTW version is used to simulate a read or write cycle and
like this, according to the informations founds, exactly set MMUSR.
MMUSR bits are set of the following manner:
MMUSR bits | PTEST level 0 | PTEST level > 0
~~~~~~~~~~ | ~~~~~~~~~~~~~ | ~~~~~~~~~~~~~~~
B (bit 15) | This bit is set if the |This bit is set if a bus error
| bit "Error Bus (B)" of |is generated during research in
| the ATC is set. |the tables.
----------------------------------------------------------------------
L (bit 14) | This bit is cleared | This bit is set if an index
| |overflow a limit during a
| |research.
----------------------------------------------------------------------
S (bit 13) | This bit is cleared | This bit is set for indicating
| |a privilege violation: if S bit
| |of one of the descriptors met
| |is set and the FC2 bit mentioned
| |in the instruction is cleared
| |(user access). S isn't defined
| |if the bit I of MMUSR is set.
----------------------------------------------------------------------
W (bit 11) | This bit is set if the | This bit is set if WP bit of
| bit WP in entry of the |one of the descriptors
| examined ATC is set. |encountred is set. Undefined
| Undefined if I is set. |if I is set.
----------------------------------------------------------------------
I (bit 10) | This bit is set if |This bit is set if one of the
| required logic address |descriptors encountred isn't
| isn't in the ATC or if |valid (DT = 0) or if B or L of
| the bit B of this entry|MMUSR are set during research.
| is set. |
----------------------------------------------------------------------
M (bit 9) | This bit is set if the |This bit is set if the encountred
| bit M of designed entry|page descriptor has its bit M
| is set. Undefined if I |set. Undefined if I is set.
| is set. |
----------------------------------------------------------------------
T (bit 6) | This bit is set if | This bit is cleared.
| mentioned logic address|
| is part of defined |
| window by TT0 and/or |
| TT1. |
----------------------------------------------------------------------
N (bits |This field is cleared | This field represents the number
2 to 0) | | of level accessed during table
| | research.
----------------------------------------------------------------------
<FC> operand can be mentioned:
·in immediate.
·by the three lower bits of a data register.
·by the register SFC or DFC.
FORMAT
<ea>
----------------------------------------=========================
|15 |14 |13 |12 |11 |10 | 9 | 8 | 7 | 6 | 5 | 4 | 3 | 2 | 1 | 0 |
|---|---|---|---|---|---|---|---|---|---|-----------|-----------|
| 1 | 1 | 1 | 1 | 0 | 0 | 0 | 0 | 0 | 0 | MODE | REGISTER |
|---|---|---|-----------|---|---|-------------------------------|
| 1 | 0 | 0 | LEVEL |R/W| A | REG | FC |
-----------------------------------------------------------------
R/W field indicates type of access used for research:
0->write access.
1->read access.
FC field indicates value of Function Codes of the address to test
10XXX The Function Codes are XXX.
01DDD The Function Codes are the bits 2 to 0 of a DDD data register.
0000 The Function Codes are specified in SFC.
0001 The Function Codes are specified in DFC.
Bit A specifies address register option:
0-> no address register
1-> address of last accessed descriptor is put in the register
specified by REG.
REG field indicates, if A = 1 the number of address register. Else
if A = 0, REG = 0.
LEVEL field indicates the highest logic level to go during research;
if test in the ATC, LEVEL = 0.
REGISTER
<ea> specifies logic address to test, allowed addressing modes are:
--------------------------------- -------------------------------
|Addressing Mode|Mode| Register | |Addressing Mode|Mode|Register|
|-------------------------------| |-----------------------------|
| Dn | - | - | | Abs.W |111 | 000 |
|-------------------------------| |-----------------------------|
| An | - | - | | Abs.L |111 | 001 |
|-------------------------------| |-----------------------------|
| (An) |010 |N° reg. An| | (d16,PC) | - | - |
|-------------------------------| |-----------------------------|
| (An)+ | - | - | | (d8,PC,Xi) | - | - |
|-------------------------------| |-----------------------------|
| -(An) | - | - | | (bd,PC,Xi) | - | - |
|-------------------------------| |-----------------------------|
| (d16,An) |101 |N° reg. An| |([bd,PC,Xi],od)| - | - |
|-------------------------------| |-----------------------------|
| (d8,An,Xi) |110 |N° reg. An| |([bd,PC],Xi,od)| - | - |
|-------------------------------| |-----------------------------|
| (bd,An,Xi) |110 |N° reg. An| | #data | - | - |
|-------------------------------| -------------------------------
|([bd,An,Xi]od) |110 |N° reg. An|
|-------------------------------|
|([bd,An],Xi,od)|110 |N° reg. An|
---------------------------------
RESULT
Not affected.
SEE ALSO
PLOAD