Model 145 Model-Dependent Fixed Storage Locations - IBM System/370 145 Manual

data stored is processed by recovery management routines. The fixed
logout area data indicates the reason for the interruption in the
machine check code and the region code. The values of the CPU timer and
clock comparator are stored in locat:ions 216 and 224, respectively,
wherever a machine check occurs, if -this feature is present in the
system. The save areas in the
logou~t
area preserve the status of the
system at the time of the machine chleck interruption and contain the
contents of the general, the floatin9-point, and the control registers.
160
Reserved
I/O COMMUNICATIONS
168
Channel ID 172 I/O extended logout pointer
AREA
176
160 - 191
Limited channel logout 180 0
*Stored for EC mode
184
0
I
* I/O address 188
0
operations only
192
~~
Unused
::~
216
Contents of CPU timer
224
Contents of clock comparator
FIXED LOGOUT AREA
232
. Machine check code
216-511
240
Region code 248
Unused
• Layout varies by System/370
252-255
Failing processor storage address
1252 IFailing control
I
Bit
I
Type of
model
• storage address corrected storage error
256
,r---
,...,
• Alwa s 10
Unused
r
y
gg ed on a machine
352
384
448
check interruption
Floating point registElr save area
't'
--------~r::t.
·
Processed by RMS
General register save area _
Control register save area
512
CPU EXTENDED LOGOUT AREA
CPU extended logout area - 192 bytes
• Model dependent
(Pointer in control register 15
set to 512 at IPL)
• Logged on all machine checks
and first and eighth micro-
instruction retry if not disabled
Figure 50. 10.3. Model 145 model-depE~ndent fixed storage locations
The model-dependent CPU extended logout area begins at the address
specified in control register 15, which is set by the hardware to
decimal location 512 by an IPL or on a system reset. The length of this
extended logout area on the Model 14S is 192 bytes. Currently, however,
only 112 bytes of this area are used., and this length instead of 192 is
stored in the machine check code. A logout to the extended area occurs
for all types of machine check
interl~ptions
if the log suppression mask
bit in control register 14 is a one. This data can be recorded by
recovery management routines.
Figure 50.10.4 illustrates the layout and the contents of the eight-
byte machine check code stored in processor storage locations 232-239.
The machine check code indicates which type of interruption occurred,
the validity of certain fields stored in the fixed logout area, and the
length of the stored CPU extended 10<Jout area. The four-byte region
code is used to further describe proc:essor and control storage errors.
The region code identifies an interruption caused by a double-bit
control storage error, a control or processor storage intermittent
failure, or the exceeding of a threshold value for single-bit control
storage errors.
A Guide to the IBM System/310 Model 145
191