ST5481 datasheet(2/18 Pages) STMICROELECTRONICS

2 / 18 page

ST5481

2/18

1 - GENERAL PURPOSE

The ST5481 is a single chip ISDN -BRI with USB

Interface low cost controller. The purpose is a low

cost ISDN modem for applications like INTERNET

ACCES and FAX capabilities when the PC is ON

(full operating mode). The bonus is to offer an

easy and lowcost access to INTERNET at a rate

of 128kbits/sec. EASY access due to plug and

play features via USB bus and lowcost due to host

processing concept and remote powering via USB

bus features.

2 - MAIN FUNCTIONS

The device controls the S0 ISDN basic rate

access (ITU normalization I430) and manages the

B1, B2, D channels through the USB bus. B1, B2,

D channels data flow is regulated through FIFO

memories of respectively 32, 32, 16 bytes in each

direction. On D, B1, B2 channels, all upper

protocols than basic HDLC framing protocol

are host processed from upper-datalink protocol

(I440 normalization),

network

protocol

applications drivers. Link Activation, deactivation

protocols (I430) is managed by the device. But the

full handling of the command and indicate

primitives

done

the

host

processor

accessing to dedicated registers. Call setup

signalling frames through D channel are managed

by the host processor.

Internal regulators can be enabled to feed the

device (and external devices) via the GNDBUS,

VBUS USB powering lines. They convert the USB

5 volts to 3.3 volts.

The device respects the USB release 1.0 power

management recommendations. When entered in

suspend mode on USB side the device drop into a

low power mode. An internal oscillator and a PLL

provide from an external 15.36MHz crystal a

48MHz clock for USB data rate recovering and

15.36MHz clock for S interface.

The device offers one operating mode called

CLOSED mode plus several test modes. In

CLOSED MODE the device presents the USB

interface, the S interface and 8 GPIO pins.

3 - PIN-OUT

Figure 1 : Pin-out Synoptic

GPIO7

GPIO6

GPIO5

GPIO4

GNDD1

GPIO3

GPIO2

GPIO1

GPIO0

XTALIN

XTALOUT

FLTPLL

LIP

LIN

IREF

LON

LOP

TEST13

TEST12

NCS_TEST11

SDI_TEST10

CFG1_TEST9

SDO_TEST8

SCK_TEST7

ST5481

ST5481 数据表(PDF) 2 Page - STMicroelectronics

ST5481 数据表(HTML) 2 Page - STMicroelectronics

Html Pages

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18

数据表下载