Specifications

Specifications
STD Bus Loading Characteristics
The unit load is a convenient method for specifying the input and
output drive capability of STD bus cards. In the STD bus systems,
one unit load is equal to one LSTTL load as follows:
• Maximum high level input current: 20 µA
• Maximum low level input current: -400 µA
The STD bus unit load reflects input current requirements at worst
case conditions over the recommended supply voltage and ambient
temperature ranges. An output rate at 60 unit loads can drive 60 STD
bus cards having input rated at one unit load.
Table B-1, "ZT 8832 STD Bus Loading, P Connector," includes load
values for STD 32 P pins. Table B-2, "ZT 8832 STD Bus Loading, E
Connector," includes load values for STD 32 E pins.
Notes for Table B-1:
REQ indicates required connection
[1]
High order address bits multiplexed over databus
[2]
PCI connected to PCO
Notes for Table B-2:
REQ indicates required connection
B-3