Intersil ISL1208, Application Note

Page: 8 / 10

8
AN1176.0
June 20, 2005
Using the RTC-USB Motherboard with
Older X1227 Daughtercards
The RTC-USB board is compatible with and can be used
with the older X1227 daughtercards that were supplied with
the serial-port based evaluation platform, similar to the USB
platform. The USB motherboard will actually detect the
X1227 daughtercard and enable communications with that
register set. Here are the specifics required:
1. Plug the daughtercard into the motherboard then plug
into the USB cable. Then open the software which will run
the detection program.
2. Once the software is running, all functions available on
the eval board can be used. Note that there is no temp
sensor on the X1227 daughtercard, so there is no temp
monitoring available.
3. The X1227 device has a watchdog timer function that can
inhibit communications if it is enabled. To disable it, you
must repeatedly write to the BL register of the X1227 (see
the X1227 data sheet) until the write is accepted by the
device.
RTC Motherboard Bill of Materials
DESIGNATOR PART TYPE FOOTPRINT DESCRIPTION MFR PART # MFR PART NUMBER
BT1 CR2032 Socket BATTX Battery and Socket MPD BS-3-ND Panasonic
or other
CR2032
C1 0.1µF 1206 0.1µF 50v X7R
Ceramic Aurface
Mount
AVX 12065C104KAT2A * *
C10 0.22F SCAP SCAP 0.22F 5.5V Super
Cap - Through Hole
Panasonic EEC-S0HD224H DigiKey P10788-ND
C2 0.1µF 1206 0.1µF 50v X7R
Ceramic Surface
Mount
AVX 12065C104KAT2A * *
C3 18pF 1206 22pF 50v NPO
Ceramic Surface
Mount
AVX 08055A220KAT2A * *
C4 18pF 1206 Capacitor AVX 08055A220KAT2A * *
C5 10µF CAP SMB 10µF 10v Tantalum
Surface Mount
Panasonic ECS-T1AY106R * *
C6 0.01µF 805 Capacitor * *
C7 0.1µF 1206 Capacitor * *
C8 20p 1206 Capacitor * *
C9 20p 1206 Capacitor * *
C11 0.033µF 1206 Capacitor * *
CN1 CN-USB USB_CONN Molex 67068-1000
D1 1N4148 MiniMELF Diode * *
FB1 FERRITE
BEAD
805 DigiKey #
240-1018-1
*
J1 CON2 CONN_2 Connector * *
J3 CON1 CONN_1 Connector * *
J2 CON10 CONN_10 Connector Samtec TSW-110-08-
G-S-RA
JP1 HEADER 3 CONN_3 Single Row Header,
Breakaway, Tin Finish,
Straight
Molex * *
JP2 HEADER 3X2 CONN_3X2 Dual Row Header,
Breakaway, Tin Finish,
Straight
Molex * *
Application Note 1176