M381: 1024 Byte ROM

The M382 is a 8192 Bits MOS Read Only Memory organized as 1024 words by 8 bits.
The ROM is designed for the M 38 microcomputer system and can be directly connected to the M 38 system buses without any additional logic.
The unit includes:

• 1 K byte ROM .
• The 11 bit registers Q, RA, RB, Z. These are organized as a Stack and the information stored in them can be moved up and down by control commands.
• The ROM address is stored in the Q register and the content can be incremented on command.
  In some cases the Z register can be used to address the ROM: the selection of Q or Z is done by the control logic and is a function of the control lines status.
  The Q and Z register contents can be changed by storing ADB bits 3/2/1 into Q bits 11/10/9 or Z (bits 11/10/9) and DAB into Q or Z (bit 8 to 1): this is done by commands decoded from the control lines.
• Two I/0 ports of 8 bits:
  Through each I/0 port it is possible to transfer information into the data bus from 8 lines of a peripheral or to store the data bus information into 8 flip-flops whose output is connected to the same 8 lines.
• The masked module code assigned to the unit during system design and the logic to compare this code with the informations on the address bus.
• The module codes are build onto the chip by the custom mask/interconnect process.

More details: M380 uP System and Instruction Set. SGS/ATES