SMS64

Preliminary

Summit Microelectronics, Inc

2060 2.22 10/09/03

2

GENERAL DESCRIPTION

The SMS64 has four major functional blocks; the

supply managers and the sequencing outputs; the

programmable reset and interrupt circuitry; the timing

and control block; and the nonvolatile memory array.

The managers are comprised of a voltage monitor

with a programmable threshold input. The monitored

voltage threshold can be programmed anywhere

between 0.9V and 6.0V in 20mV increments. Each

monitor

provides

an

under-voltage/over-voltage

(UV/OV) signal to the internal bus.

Associated with each monitor is an output circuit

(PUP circuit) that can be used to enable or switch an

external power supply to the application’s circuits. The

point in time and position in a sequence when the

output is asserted is programmable and is controlled

by the sequence position assignments and the PUP

delays in the timing and control block.

The other major block is a programmable reset and

interrupt block. The SMS64 provides a great deal of

flexibility in choosing the trigger source for the resets

and

interrupt.

The

sources

include

multiple

combinations of UV/OV conditions, and programmable

Watchdog and Longdog timers.

Programming of the SMS64 is performed over the

industry standard I

allows configuration of the device, real-time control of

the power-on/power-off processes and instant-access

to the power supply status of the application circuit.

The bus interfaces the host to 4k bits of nonvolatile

memory

and

the

programmable

configuration

registers.

2.5V

2.7V

1.8V

---

RST_B#

RST_A#

2.0V

1.5V

3.3V

Figure 1 – Example Power Supply Sequencing and System Start-up Initialization using the SMS64 as

shown in the Simplified Applications Drawing on page 1. Any order of supply sequencing can be applied

using the SMS64