The most significant ALU output bit. The generate and propagate outputs of the ALU, can be used to for cary-lookahead. OVR O Overflow. Indicates the result of an arithmetic two's complement operation has overflowed into the sign bit. I O The input and output shift lines for the LSB and MSB of the register stack.
Dual lines allow for shift up and shift down operations.
RAM0O is valid when OE0N is low and RAM3O is valid when OE3N is low. O Data outputs. These outputs are connected to either ALU or A port of the register stack. O When low indicates Q0O and RAM0O are valid. O When low indicates Q3O and RAM3O are valid.