DS1673

The DS1673 provides a Real Time Clock, NV RAM controller, microprocessor monitor, and a 3-channel, 8-bit analog-to-digital converter.Communication with the DS1673 is established through a simple 3-wire interface.The Portable System Controller is a circuit which incorporates many of the functions necessary for low power portable products integrated into one chip.All data transfers are initiated by driving the CS input high.The CS input serves two functions.  First, CS turns on the control logic which allows access to the shift register for the address/command sequence.Second, the CS signal provides a method of terminating either single byte or multiple byte (burst) data transfer.A clock cycle is a sequence of a rising edge followed by a falling edge.

Features of the DS1673 are:(1)counts seconds, minutes, hours, date of the month, month, day of the week, and year with leap year compensation valid up to 2100; (2)power control circuitry supports system power on from day/time alarm; (3)halts microprocessor during power-fail; (4)automatically restarts microprocessor after power failure; (5)monitors pushbutton for external override; (6)halts and resets an out of control microprocessor; (7)automatic battery backup and write protection to external SRAM; (8)3-channel, 8-bit analog-to-digital converter; (9)simple 3-wire interface; (10)+3.0 or +5.0V operation.

The absolute maximum ratings of the DS1673 can be summarized as:(1)voltage on any pin relative to ground:-0.3 to 7.0V;(2)storage temperature:-55 to 125;(3)operating temperature:0 to 70;(4)soldering temperature:see J-STD-020A.Data transfers can occur 1 byte at a time or in multiple byte burst mode.  After CS is driven high an address is written to the DS1673.  After the address, 1 or more data bytes can be read or written.For a single-byte transfer 1 byte is read or written and then CS is driven low.  For a multiple-byte transfer,multiple bytes can be read or written to the DS1673 after the address has been written.Each read or write cycle causes the register address to automatically increment.Incrementing continues until the device is disabled.After accessing register 0Eh, the address wraps to 00h.