PARALLEL I/O A1A3A10 DATA INPUT AND SELECTOR CIRCUIT.

T.O. 31S5-4-308-l

TM 11-5805-663-14-13

NAVELEX 0967-464-0010

output of Gl is inverted by inverter I1 which

5-402. STRB-N is inverte

triggers FF1. The output of FFl activates

which generates STRA-P (wav

gate G5 if SELl-N is high (no other function

45). STRA-P activates gate

requesting INFIBUS access). The output of

FF3. The 0 output of FF3 en

G5 sets FF2 and disables gates G2 and G6.

G5 and the i output of FF

The output of FF2 enables G2 and G6 and

G8. Clearing FF3 causes SACK-N to return

also activates gate G4. The output of G4

to high. After data is transferred, DONE-N

is coupled through driver DRl which gener-

(waveform M, figure 45) is received.

ates SRLl-N (waveform E, figure 45).

DONE-N is inverted by inveter I3 which

generates BDNA-P (waveform N, figure 45)

5-400. The Bus Controller receives SRLl-N

BDNA-P activates G13, G14, and is a

and returns SELl-N, (waveform F, figure

inverted by inverter I2. The output of Gl

45) and the precedance pulse PCDA-P (wave-

sets FF5 and activates G11 which resets

form G, figure 45). SELl-N disables G5

FFl. The output of I2 disables gates G7

which enables G6 and activates G2. Gate

and G10. With FF5 set, G10 is enabled

G3 is disabled by the output of G2. G3 is

and when DONE-N is removed, BDNA-P

normally enabled and will couple PCDA-P

will go low which disables G13 arid G14.

to the INFIBUS as PCDB-P if an INFIBUS

The output of I2 now activates G10 which

access is not being requested. When an

clears FF4. The output of G14 (high) dis-

INFIBUS access is being requested G3 is

ables G12 which causes BOLA-P to go low.

disabled and PCDB-P is not coupled to

BOLA-P now disables G16 which removes

the INFIBUS.

STRB-N. Clearing FF4 disables G9 and

G14, clears FF5, and enables G5.

5-401. PCDA-P, when received, activates

5-403. If DONE-N is not received within

G6 which disables gate G8 and sets FF3.

2 usec after STRB-N goes low, the Bus

The 0 output of FF3 disables gates G4

Controller generates QUIT-N. Inverter I4

and G5 and is coupled through driver DR2

inverts QUIT-N which activates gate G15

which generates SACK-N (waveform H,

(G15 enabled by BOLA-P during the normal

figure 45). The Bus Controller detects

c y c l e ) . The output of G15 clears FF3 and

SACK-N and removes SELl-N. G5 is again

FF4 and activates G11 which resets FFl.

enabled by SELl-N (high) but disabled by

Inverter 15 inverts the output of I4 which

the 0 output of FF3. The 1 output of FF3

disables G7 to allow G15 to clear FF4.

enables gate G8. When PCDA-P returns

to low G6 is disabled and activates G8.

5-404. PARALLEL I/O A1A3A10 DATA INPUT

The output of G8 clears FF2 which disables

AND SELECTOR CIRCUIT.

G2, G4, and G6. With G2 disabled, G3

is enabled and PCDA-P can be coupled to

5-405. General. The Parallel I/O data

the INFIBUS. The 1 output of FF3 also

input and selector circuit receives data

activates gate G7. The output of G7 sets

from the Alarm Control and VF Comm Link

FF4 and activates gate G12. The 0 output

function and selects the data that is to

of FF4 disables G5 and the 1 output of FF4

be placed on the INFIBUS data lines.

enables gates G9 and G13 and activates

VF Comm

Data from the Alarm Control a

gate G14 (FFS cleared). G14 generates

data

Link is temporarily stored by

BONE-N (waveform I, figure 45) and acti-

input register and the data selectors

vates G12 which generates BOLA-P (wave-

select one of four following data input

form J, figure 4.5). BOLA-P and BONE-N

groups: data from the Alarm Control

enable the device number to be strobed to

and VF Comm Link function, control regis-

the INFIBUS data lines. BOLA-P also

ter contents, anti Parallel l/O status, or

enables gates G15 and G16 and is inverted

the Parallel I/O address (device number).

by inverter I7. The output of I7 is delayed

Detail Analysis (see figure 46).

5-406.

50 nsec by delay DLl. The output of DLl

The input data register is controlled by the

activates G16 generating STRB-N (wave-

form K, figure 45).

5-58