Eurotech BitsyXb - Real-Time Clock (RTC); Adsmartio; Overview

Feature Reference
110118-0001A 27
GP
Signal Name
Type
Function (connector, section)
107
EIO9
108
DIP_SW1
109
SD_DAT1
IO
SD/MMC (J7, 4.5.5)
110
SD_DAT2
IO
111
SD_DAT3
IO
112
SD_CMD
IO
113
RESET_AUDIO_L
114
/IRQ_BATT_
FAULT
115
/SD_WP
I
SD/MMC (J7, 4.5.5)
116
/SD_CD
I
117
n/c
118
n/c
4.2 Real-Time Clock (RTC)
The BitsyXb uses the DS1307 real-time clock chip to maintain the system date and time when the
system is powered down. The operating system typically reads the RTC on boot and wakeup, and
sets the RTC when the system time or date is changed.
The RTC is powered from the BATPOS input. Connect a long-life 3 V battery to the BATPOS
input (J3 pin 50) to maintain the system time.
The system communicates with the RTC on the I
2
C bus (section 4.5.4). See section 6.3.4 for
electrical specifications.
4.3 ADSmartIO
ADSmartIO
TM
is a RISC microcontroller on the BitsyXb that is programmed with Eurotech
firmware. This device provides additional I/O functionality for specialized tasks. Your
application software can configure the standard ADSmartIO for a variety of functions, such as
digital I/O, PWM, A/D, I
2
C, keypad scan and PS/2 keyboard operation.
4.3.1 Overview
The ADSmartIO controller has four, eight-pin I/O ports named PA, PB, PC and PD. Some of
these ports' pins are used internally, while others are available for user applications. See the signal
cross-reference in section 4.3.7 for details.
Generally, ADSmartIO ports are referenced by port and pin number (e.g. PA2), but I/O signals
may go by several names based on its functionality. See the connector pinouts to cross-reference
ADSmartIO signal names.
Electrical specifications for the ADSmartIO are listed in section 6.3.6. The ADSmartIO
Programmer's Reference (Eurotech document #110110-4004) gives information about how to use
the ADSmartIO features.