www.ezurio.com

Pin 8 (UART_DCD) is active low. It is normally 3.3v. When a connection is live this pin is low. This means that when this pin is converted to RS232 voltage levels it will have the correct voltage level for assertion.

Pin 10 (UART_DSR) is an input, with active low logic. It should be connected to the DTR output of the host. When the BISM2 Module is in high speed mode (See definition for S Register 507), this pin should be asserted by the host to ensure that the connection is maintained. A deassertion is taken to mean that the connection should be dropped, or an online command mode is being requested.

Pin 27 (VCC_3V3 monitor) may only be used for monitoring purposes. It must not be used as a current source.

The GPIO pins can be accessed using S Registers 621 to 628. GPIO4 is connected to an LED on the module. If these I/O pins are set for input, then the LED will be driven by the host and appropriate drive current requirements must be satisfied. A Logic 1 switches on the LED.

GPIO3 is also used for DTR output (active low). See S Register 552 & 553.

Analogue 0 and 1 should not exceed 1.8v and S Registers 701 and 702 are used to access them.

3.3Electrical Specifications

3.3.1Absolute Maximum ratings

Absolute maximum ratings for supply voltage and voltages on digital and analogue pins of the Module are listed below; exceeding these values will cause permanent damage.

Parameter

Peak current of power supply

Voltage at digital pins

Voltage at POWER pin

Min

0

-0.3

3.6

Max

100

3.7

7

Unit

mA

V

V

3.3.2Recommended Operating Parameters

3.3.2.1Power Supply

Signal Name

Pin No

I/O

Voltage level

Comments

 

 

 

 

 

Vcc

29

I

3.6V to 7.0V

Ityp = 30mA

 

 

 

 

 

GND

11, 15, 18,

 

 

6 Ground terminals to be attached

 

30, 36, 38

 

 

in parallel

 

 

 

 

 

VCC_3V3

27

O

3.3V typical

For monitoring only. No current

 

 

 

 

source

 

 

 

 

 

3.3.2.2RS-232 Interface

Signal Name

Pin No

I/O

Signal level

Comments

 

 

 

 

 

UART_TX

21

O

VOLmax=0.2V

 

 

 

 

VOHmin=2.8V

 

 

 

 

 

 

UART_RX

25

I

VILmax=0.8V

 

 

 

 

VIHmin=2.1V

 

 

 

 

VIHmax=3.7V

 

 

 

 

 

 

UART_CTS

19

I

VILmax=0.8V

 

 

 

 

VIHmin=2.1V

 

 

 

 

VIHmax=3.7V

 

 

 

 

 

 

Page 5
Image 5
Oki BISM2 manual Electrical Specifications, Absolute Maximum ratings, Recommended Operating Parameters, Power Supply