| CF | ||
|---|---|---|
 | 84.1.1. Abecední přehled instrukcí Whirlwind |  |
| CF | ||
|---|---|---|
| | 84.1.1. Abecední přehled instrukcí Whirlwind | |
CF — sum digits
CF pqrThe address sectiondoes not refer to a register of storage in this instruction, but supplies information to the computer requesting a change in fields Group A and/or B. When the fields to be changed contains the program, it is necessary for the cf instruction to perform like an SP instruction. Digit 7 of the cf address section causes the contents of the accumulator to be read to the program counter (PC) prior to the field change; thus, program continuity can be preserved during field changes. The A-Register will contain the original PC address plus one upon completion of the cf instruction. The digit allocation for the cf word is as follows:
| bity | význam |
|---|---|
| 0-4 | 00111 — instrukce cf |
| 5 | nepoužito |
| 6 | examine feature — causes contents of core memory Group A control and Group B control registers to be read into the Accumulator. |
| 7 | sp enable — reads content of AC to PC to establish starting point of program in the new field. |
| 8 | change Group A field enable. (If, when the examine feature of digit 6 is requested, there is a "1" in digit 8, the content of Group A control will be changed before read-out to the A-Register takes place. |
| 9 | change Group B field enable. (If, when the cf examination feature is requested, there is a "1" in digit 9, the content of Group B control will be changed before read-out to the A-Register takes place. |
| 10-12 | contain field designation for Group A (registers 40-1777) |
| 13-15 | contain field designation for Group B (registers 2000-3777) |
| CF | 00111 xxxAB aaa bbb |
| |  | |
| CA |  | CK |
