IBM System/7 Functional Characteristics - All about the IBM 1130 ...

I/0 CommandsThe prepare I/O and halt I/O commands are used as described in Chapter 4 under"Input/Output Instruction" and in this chapter under "Module Device Addresses."Immediate read and immediate write commands transfer data between the analog inputcontrol and the processor module. The setting of the modifier field bits in the commandfurther defines the operation to be performed.In all I/O commands addressed to analog input, the device address field contents mustbe 100100. The module address varies depending upon the physical location of the multifunctionmodule in the 5026 Enclosure.Usually, a complete operation is performed within the time limit required for executionof the immediate commands. Exceptions to this rule are three convert commands that startthe conversion cycle and then permit the program to resume normal operation while awaitingthe interruption request presented by the module at the end of the conversion cycle.Executing any of the three commands sets on the ISW device-busy bit, which remains onduring the conversion time. When the conversion is complete, an interruption request ispresented to the processor, the device-busy bit is turned off, and the device-end bit isturned on. Condition code 2 is returned to all immediate commands issued to this deviceaddress (except read ISW) while the module is busy or has a pending interruption.The normal analog input programming routine is shown in Figure F-1 of "Appendix F."Convert Analog Input0 5 8 11 16 20 26 31Op codeRFunZerosMod0 0 0 0 1 XXX 0 0 1 0 0 0 0 0 0 0 0 0 1 0 0 1 0 0 XXXXXXMI ii 11 iiil 1111 1111 11111.........,...../•■•••■•••••'00.Y.••••••••■■•••••••••••••■■■••••• "•••••••■••••••"0 8-F 2 0 0 9 0-3 XDAMAThis command starts an analog-to-digital conversion cycle based upon control informationcontained in the index register (R), or the accumulator if R=000. The control informationword has the format:0 15Not usedMpxr addr• • • • • R RR 0 0 OXX X XX1 1 1 1111111•••■•■•••,...M./ ••■•■••.,■10.4.0 0-7 0-1The range bits (RRR) in the control word specify the input voltage range and the amplifiergain desired, as shown in the following table.RRR Bits • Input Voltage Range Amplifier Gain000 — Automatic gain001 +10 mV 512010 ±20 mV 256011 +40 mV 128100 +80 mV 64101 +160 mV 32110 +640 mV 8111 ±5.12V 1- , , ,11111111111•M 1.111111■11111.111111111111.1111111M1 11111111111 1111111111M 111111M