| General Description |
The Am2910 Microprogram Controller is an address sequencer, intended for controlling the sequence of executions stored in microprogram memory.
It provides sequencial access and conditional branching to any instruction within it's 4096-microword range.
A last-in, first-out stack provides microsubroutine return linkage, with 5 levels of nesting.
Microinstruction loop count control is provided with a maximum count of 4096.
This is part of the 2900 chipset family, and is a support chip for the Am2901. |
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| Address Bus Width |
Twelve Bits Wide
Address up to 4096 words of microcode with one chip.
All internal elements are a full 12 bits wide. |
| Internal Loop Counter |
Pre-settable 12-bit down-counter for repeating instructions and counting loop iterations. |
| Four Address Sources |
Microprogram Address may be selected from:
microprogram counter
branch address bus
5-level push/pop stack
internal holding register |
| Sixteen Powerful Microinstructions |
Executes 16 sequence control instructions, most of which are conditional on external condition input, state of internal loop counter, or both. |
| Branch Address Sources |
Output Enable Control for Three Branch Address Sources.
Built-in decoder function to enable external devices onto branch address bus. Eliminates external decoder. |
| Edge-triggered registers |
All Registers Positive Edge-triggered
Simplifies timing problems.Eliminates long set-up times. |
| Conditional Response |
Fast Control from Condition Input.
Delay from condition code input to address output only 21ns typical. |
