HP 3562A Service Manual page 309

MODE L 3 562A
Internal Signal Descriptions
ClRPG L
D I R1
D I R 2
E N A B LE D L
E PO t o EP7
KACKL
KAS
Il D n f. .... Il D '7
. " .... '" I. " I' Ll J
• " "--"""" �-. m_"
KRD
KROM L
C L EAR ROTAT I O N P U LS E G E N E RATOR (RPG)
Active Low
Output of the keyboard device decod er. This si gnal c l ears the turn
and interrupt latc hes.
D I RECT I O N of ROTAT IO N of RPG1
D i rection l atch 1 send D I R1 to the keyboard processor to i nd i cate
which d i rection the m arker RPG has been rotated .
D I R E C T I O N of ROTAT I O N of RPG2
D i rection l atch 2 sends DI R2 to the keyboard processor to i nd i cate
which d irection the parameter RPG has been rotated .
E N A B L E D PARAM E T E R
Active Low
The L E Ds l atch 1 sets E NA B L E D L low to l ight the E nable L E D and
activate Turn Latch 2.
E P ROMO to E P ROM7
The keyboard E P ROM sends instructions to the keyboard p rocessor
u s i n g these l i nes.
KEY BOARD ACK N OW L E D G E
Active Low
S ignal from the keyboard device decoder to clock DTAC K L out to the
A2 System C PU .
K E Y BOARD A D D R E S S STRO B E
Signal from the keyboard processor indi cati ng addresses KAB to KA1 2
are val id .
V C V D r\ A D n D I I C 1 I !.. I !: C
'"\' L ' v '-' '' ' ' u v u .:> L I I 'I L: ':> U
Keyboard data l i nes the keyboard processor uses for input and output.
is val id d ata on K BO to K B7.
K E Y BOARD R E A D/W R I T E
T h i s s i g n a l dete r m i n es whether the keyboard p rocesso r is read i n g o r
writi ng on data l i nes K BO to K B7 . The keyboard control ci rcu itry also
uses KRD to set up i n put and output ope rations for the keyboard.
K E Y BOARD ROM
Active Low
T h i s signal from the keyboard device decoder enab les the i n stru ction
ROM l i nes E PO to E P7.
{\ L L _ L "7
.
_ _ .
I
l I l I U U g l 1
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C I R C U I T D E SC R I PT I O N S
6-91