3.20.1

Power Regions

STA8135GA has six major power regions. The modules present inside each power region are given below.

•

Always on backup region: 1.2 V

–

prcc_backup

–

RTC

–

Backup RAM 256 bytes

•

Switchable region: 1.2 V

–

ARM® core

–

Other digital IPs

•

RF: 1.1 V

•

OTP: 2.5 V

•

IO ring1: 1.8 V or 3.3 V

•

IO ring2: 3.3 V

By default IO ring1 is at 1.8 V supplied by internal LDO IO. If IO ring1 has to be at 3.3 V then external supply must

be applied on VIO1 at 3.3 V.

The switchable power region can be supplied by an external voltage regulator directly at pin VDD_EXT_REG. The

integrated LDO CORE has to be switched off by forcing EXT_REG_SEL to high voltage.

The usage of the external regulator to supply the switchable power region is mandatory in applications that

require to sustain 105 °C.

3.21

I2C high speed controller

One I2C high speed controller interface is capable of master/slave modes in multi-master environment. It is DMA

capable and multiple baud rates are supported: 100/400/1000/3400 Kbits/s.

3.22

Full speed USB 2.0

It supports 12 Mbps (full speed) and 1.5 Mbps (low speed) serial data transmission according to USB 2.0 OTG

controller specification.

3.23

SDMMC (Secure Digital Multi Media Card Controller)

The SDMMC card host interface provides an interface between the APB peripheral bus and Multi Media cards

(MMC), SD memory cards, SDIO cards, and CE-ATA devices.

STA8135GA

I2C high speed controller

DB4575 - Rev 1

page 20/29