pdp11_mmu.vhd: BUGFIX: correct trap and PDR A logic

- tools/asm-11/lib/defs_mmu.mac: rename md.a??, saner names for ACF
- tcode/cpu_mmu.mac: add E1.1, test m0.trp, pdr aia/aiw transitions (verify fix)

Closes #34
Closes #33
Closes #26
Closes #25

doc/CHANGELOG.md

@@ -36,7 +36,7 @@ The full set of tests is only run for tagged releases.
 - remove Atlys support (only test designs, a w11 design was never done)
 - cleanup SimH setup files (\*.scmd), use autoconfig, set disk types
 - cleanup code base, use page,mmr\*,pdr,par instead of segment,ssr\*,sdr,sar
-- sysid encodes now system type, allows to distingish w11,SimH,e11
+- sysid encodes now system type, allows to distinguish w11,SimH,e11
 - added dasm-11, a PDP-11 disassembler
 ### New features
 - new verification codes
@@ -90,12 +90,15 @@ The full set of tests is only run for tagged releases.
     - *.scmd:      set sysid to 110234 --> emu Simh
     - *.ecmd:      set sysid to 120345 --> emu e11
 ### Bug Fixes
+  - rtl/w11a
+    - pdp11_mmu: BUGFIX: correct trap and PDR A logic, see
+        [ECO-033](ECO-033-MMU_AFC-1_PDR-A.md)
+  - src/librwxxtpp
+    - RtclRw11Cpu.cpp: quit before mem write if asm-11 error seen
   - tools/asm-11/lib
     - tcode_std_start.mac: fix sdreg probe code
   - tools/mcode
     - m9312/bootw11.mac: proper init of unit number in getnam
-  - src/librwxxtpp
-    - RtclRw11Cpu.cpp: quit before mem write if asm-11 error seen
 
 <!-- --------------------------------------------------------------------- -->
 ---

doc/ECO-033-MMU_AFC-1_PDR-A.md

@@ -0,0 +1,58 @@
+# ECO-033:  MMU: ACF=1 trap and PDR A fix (2022-09-07)
+
+### Scope
+- was in w11a since 2009
+- affects: all w11a systems
+
+### Symptom summary
+- part 1: ACF=1 traps on any access  
+  Test 055 of `ekbee1` fails with
+  ```
+      MEMORY MANAGEMENT TRAP OR ABORT HAD INCORRECT CONDITION
+      EXPECTD ERROR   AUTOI/D VIRTUAL
+      CONDITN REGISTR REGISTR ADDRESS TESTNO  PC AT ABORT
+      020011  030011  013427  054032  000055  054040
+  ```
+
+- part 2: `PDR` A bit is set for every access  
+  This was discovered in a code review. The `PDR` A bit was set for
+  all accesses.  The `PDR` A bit should be set only when
+  _"trap condition met by the Access Control Field (ACF)"_ is fulfilled.
+  Thus for
+  ```
+     ACF=001 read-only    trap and A bit on read
+     ACF=100 read/write   trap and A bit on read or write
+     ACF=101 read/write   trap and A bit on write
+  ```
+
+  `ekbee1` only checks whether this bit is set when expected, but does
+  _not_ verify that is stays '0' when it should.
+
+### Analysis
+- part 1: ACF=1 traps on any access
+  Caused by a simple mistake in the `ACF` handling in pdp11_mmu.vhd
+  ```vhdl
+      case PARPDR.acf is                -- evaluate accecc control field
+      when "001" =>                     -- read-only; trap on read
+        if CNTL.wacc='1' or CNTL.macc='1' then
+          abo_rdonly := '1';
+        end if;
+        dotrap := '1';                  -- <== BUG, should be 'not write'
+  ```
+- part 2: PDR A bit is set for every access
+  Caused simplistic AIB handling in pdp11_mmu.vhd
+  ```vhdl
+        if doabort = '0' then
+          AIB_SETA <= '1';              -- <== BUG, should be 'dotrap'
+          AIB_SETW <= CNTL.wacc or CNTL.macc;
+        end if;
+  ```
+
+### Fixes
+- part 1: `AIB_SETA <= dotrap;`
+- part 2: `dotrap := not iswrite;`
+
+### Hindsight
+Took 13 years to fix. The MMU traps and `PDR` A and W bits are 11/45 and 11/70
+specific and not used by any operating system. Only tests like `ekbee1` use
+this functionality.