HP 3000 SERIES II System Service Manual page 93

FRONT
+
SELECTOR CHANNEL
MAINTENANCE PCA
30033
Maintenance Procedures
CHAN SR
~
J
J
J
J J J
CHAN SO
CHAN ACK
XFER ERR
EOT
TOGGLE IN XFER
TOGGLE OUT XFER
TOGGLE SIO OK
CONNECTJ10F
MAINT PCA TO J3
OF 1A1 (MAINT PNL
INTRFCI TO DISPLAY
SEL CHAN BUS
CONTROL SIGNALS.
o
I • I •
3
• • • •
• I •
•
....
• I. • • • • • I
~~
. ..........,
III
L
L
bit~~T
I N T
PREADSTB
P WRITE STB
P STAT STB
P CONT STB
P CMD 1
CONNECT J'2 OF
SELECTED REGISTER
MAINT PCA TO J3 6 7 8
10
11
1.;
13 14 15
OF 1A1 (MAINT PNL
I
• I • I
....
INTRFC) TO DISPLAY
• • • • • • • • • • • • • •
....
SEL CHAN BUS
DATA LINES.
SR
0
7 8
10
11 12 13 14 15
'\
/
V
SEL CHAN BUS DATA LINES
SELECTED REGISTER
CONNECT J3 OF
0 6 7 8
9
10 11
12
13
14 15
MAINT PCA TO J3
I
I •
I
• I • I
• I
I
....
OF 1A1 (MAINT PNL
•
• •
•
• •
• • • • •
....
INTRFC) TO DISPLAY
•
lOP BUS DATA LINES.
100
0
3 10
11
12 13 ; 14 15
'\ /
V
lOP BUS DATA LINES
522-34
Figure 4-1. SCMB State Display
4-14. PROGRAMMING
The principal components illustrated in figure 4-2 comprise the SCMB. Like any device controller, the
SCMB is programmed through the use of direct I/O instructions issued by the CPU/lOP and through
I/O program orders executed by the selector channel. SCMB operation is initially configured when a
control word is issued by a direct Control I/O instruction. To initiate execution of an I/O program (and
therefore channel operation) an SIO instruction is issued to the SCMB. The SCMB also provides a
16-bit status word to report on various maintenance PCA and selector channel operating conditions.
4-7