Datasheet

STOTG04E Block description

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6.6 Control logic

This block controls the behavior of whole chip. It communicates with the external environment via the I

serial bus. The control logic block consists of I

C slave interface, configuration and status registers, and

some glue logic.

6.7 Modes of operation

The STOTG04 can operate in two different power modes and in three operating modes. They can be

controlled by logic signals and control registers.

6.7.1 Power modes

When there is no need for the USB function, the STOTG04 reduces power consumption by implementing

the Power-down mode. The power modes can be controlled by the Suspend Bit of Control Register 1 or/

and the SUSPEND pin (see Table 8).

Table 8. Power modes

Although in power down mode all analog blocks should be switched off, some of them could be turned on

by bits in the control registers having higher priority than suspend bit. In order to obtain minimum power

consumption in power down mode the device must be configured has shown in Table 9. The digital part is

fully static so that it almost does not consume power. All of the interrupts (except BDIS_ACON) are fully

operational in Power-down mode, as is the I

C interface.

Table 9. Power down mode setup

X = Don’t care

- = Reserved

Bit order: 0...7

6.7.2 USB Modes

The STOTG04 transceiver has two basic USB operational modes. These modes define how the digital IO

pins of the transceiver will be used. Independently of USB operating mode, some signals always have the

same function (see Table 10).

Table 10. Digital interface signals

The RCV signal is active in the VP_VM mode only. Its output driver is controlled by the OE_TP_INT/

signal. Operating modes are described below. The meanings of the DAT_VP and SE0_VM signals

depend on the mode of operation. Both of these signals can be bidirectional or unidirectional. The

SUSPEND BIT SUSPEND PIN Power Mode

normal operation

1 1 power-down

SUSPEND BIT SUSPEND PIN Control register 1 Control register 2 Control register 3

1 1 X1X0XX0- 00XX00X0 -XXXX0XX

Signal Function

RCV Differential receiver output

VP D+ single-ended receiver output

VM D- single-ended receiver output

OE_TP_INT/ Output enable signal of the differential driver