DS1991 Просмотр технического описания (PDF) - Dallas Semiconductor -> Maxim Integrated

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DS1991

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Dallas Semiconductor -> Maxim Integrated 

DS1991

1-WIRE SIGNALING

The DS1991 requires strict protocols to ensure data integrity. The protocol consists of four types of

signaling on one line: Reset Sequence with Reset Pulse and Presence Pulse, Write 0, Write 1 and Read

Data. All these signals except presence pulse are initiated by the bus master. The initialization sequence

required to begin any communication with the DS1991 is shown in Figure 10. A reset pulse followed by a

presence pulse indicates the DS1991 is ready to send or receive data given the correct ROM command

and memory function command. The bus master transmits (TX) a reset pulse (tRSTL, minimum 480 µs).

The bus master then releases the line and goes into receive mode (RX). The 1-Wire bus is pulled to a high

state via the pullup resistor. After detecting the rising edge on the data pin, the DS1991 waits (tPDH, 15-60

µs) and then transmits the presence pulse (tPDL, 60-240 µs).

ROM FUNCTIONS FLOW CHART Figure 9

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