Datasheet

www.ti.com

RESET

State Nor am l erai nOp t o Resetting InitialCondition

t <5 sm

WL(RESET)

t 10³ m

WL(RESET)

TSC2004

SBAS408E – JUNE 2007 – REVISED MARCH 2008

There are three way to reset the TSC2004. First, at power-on, a power good signal generates a prolonged reset

pulse internally to all registers.

Second, an external pin, RESET, is available to perform a system reset or allow other peripherals (such as a

display) to reset the device if the pulse meets the timing requirement (at least 10 µ s wide). Any RESET pulse less

than 5 µ s will be rejected. To accommodate the timing drift between devices because of process variation, a

RESET pulse width between 5 µ s to 10 µ s falls into the gray area that is not recognized, and the result is

undetermined; this situation should be avoided. Refer to Figure 38 for details. A good reset pulse must be low for

at least 10 µ s. There is an internal spike filter to reject spikes up to 20ns wide.

NOTE: See Timing Requirements for more information.

Figure 38. External Reset Timing

Finally, a software reset can be activated by writing a '1' to CB1.1 (bit 1 of control byte 1). It should be noted this

reset is not self-clearing so the user must write a '0' to remove the software reset.

A reset clears all registers and loads default values. A power-on reset and external (hardware) reset take

precedence over a software reset. If a software reset is not cleared by the user, it is cleared by either a power-on

reset or an external (hardware) reset.

Product Folder Link(s): TSC2004