Zilog EZ80190 Bedienungsanleitung PDF herunterladen (Seite 56)

eZ80190 Development Kit

User Manual

eZ80190 Module UM014108-0810

Real Time Clock

The onboard real-time clock can function when the system power supply

is down. An onboard capacitor (GoldCap) or external accumulator/battery

serves as a standby power supply. The M41T11 Real-Time-Clock

included on the eZ80190 Module contains Binary Coded Decimal (BCD)

counting registers for Seconds, Minutes, Hours, Day, Month, Year; it also

contains a Century bit and 56 bytes of backed-up RAM. The fully-

charged 0.1 F GoldCap bridges power outages with a maximum of 4

hours. The GoldCap, in contrast to a battery or an accumulator, offers an

advantage in that service/replacement is not necessary.

The I

C address of the RTC is D0h for Writes and D1h for Reads.

Details about the internal registers of the M41T11 Real-Time clock can be

found on the ST Microelectronics website (www.st.com

C Bus Software Emulation

The eZ80190 device contains two powerful master/slave mode I

C bus

controllers. The I

C data (SDA) and clock (SCL) pins on PD1/PD0 and

PC1/PC0 GPIO are multiplexed with the UART and SPI functions. To use

C bus operation in parallel with console and modem I/O, the module

IICSCL/IICSDA pins on connector JP2 can be linked to PA7 (IICSDA)

and PA6 (IICSCL) of the eZ80190 device. In this case, an I

C master-

mode software emulation is necessary to access I

C devices.

Using PA7/PA6 or PC1/PC0 for IICSDA/IICSCL is resistor-selectable on

the eZ80190 Module.

DC Characteristics

As different combinations of application modules are loaded onto the

eZ80Acclaim!

Development Platform, current requirements change.

Please see Table 25

on page 43 to reference current consumption values

for these different modules.

1 2 ... 51 52 53 54 55 56 57 58 59 60 61 ... 86 87

Keine Kommentare

Zilog EZ80190 Bedienungsanleitung Seite 56