HP 3562A Service Manual page 355

C I RCU I T D E SC R I PT I O N S
LDTRG L
LOW I N P UT 1
LOW I N P U T 2
MG68L
MG DF1 L
M G D F 2 L
M G F FT L
M G F P P L
M R 68L
M R D F1 L
M R D F 2 L
6-1 40
LOAD T R I G G E R
Active Low
S i g n a l fro m the A1 Dig ital Sou rce that l atches command data word
CNTLD i nto the A31 Tri gger ass e m b l y's sh ift register.
LOW I N PUT 1
LOW I N P UT 2
(A33, A35 J 300-3)
These s ig n a l s are the in puts from the front panel BNC s h e l l s to the
A33 I n put 1 and A35 I n put 2 asse m b l ies.
CPU M E MORY G RANT
Active Low
After the A2 System C P U asse rts the memory req uest l i ne, the AB
G l obal RAM retu rns a memory g rant. The memory grant s ignal c lears
the memory req uest signal (MR6BL), enables the assertion of the global
read/write signal (G R/GWL), and a l l ows the A2 System CPU to use the
global add ress bus (GA1 L to GA1 6L)
M E MO RY G RANT D I G I TAL F I LT E R C H AN N E L 1
M E MO RY G RANT D I G I TA L F I LT E R C H AN N E L 2
Active Low
The AB G l obal RAM responds to bus requ ests MRDF1 L and M R D F2 L
by assertion of MG D F1 L or MG D F2 L . The two memory grant s i g n a l s
are asserted f o r about 41 0 n s . The g lobal RAM expects val id data to
be on the bus with i n 80 ns after the memory grant is given.
FFT M E MO RY G RA N T
Active Low
(A9 T P3)
After the A9 FFT asserts the memory request l i ne, the AB G l obal RAM
retu rns a mem ory grant. The memory grant signal c l ears the mem ory
req uest s i g n a l (M RFFT) and enab les the assertion of the global
read/write signa! (G RjG W L).
F P P M E MORY G RANT
retu rns a mem ory g rant. T h e mem ory grant s i g n a l clears t h e mem ory
req u est signal (M RFPP) and enab les the assertion of the global
read/write signal (G R/G W L).
C P U M E MORY R E Q U E ST
Active Low
The A2 System C P U asserts the memory request l i n e when it wish es
to add ress the A8 G lobal RAM.
M EMORY R E Q U E ST C H A N N E L 1
M E MORY R E Q U E ST C H A N N E L 2
Active Low
These two signals are f ro m the A5 Digital F i lter to AB G lobal RAM
to req uest use of the global bus for c h a n n e l 1 data or c h a n nel 2 data.
MOD E L 3562A