Page 132 - Making PIC Microcontroller Instruments and Controllers

I22 CLOCKS. MEMOEY. AND SOCKEIS

1 40
2 39
3 38
37
5 36
6 35
34
o I 33
o 9 32
o- 1 0 31
30
1 2 29
1 3 28
27
1 5 26
1 6 25
1 7 24
1 8 23
l 9 22
20 21

BEAL.TIME 2
CLOCK, OPTION

::lliiilftaafgli: clock implemenled usins lc Ds1202. (To the [.lcu, this clock lC looks
like a set ol memorv locallons.)

Nole 2 Therc are a total of si:( enpty sockets-U3, U4, U5, U6, U7, and Ult).--an
the IAR-XI boa a! rcceirea. Though more than one socket can be occupied b! an IC
at anl one tine, it is best if onlj one IC is e:cperimented ithata ! one time. This v,ill
ensufe that there are no conficts betureen the wrious derices. IJ the e{treme right
R5485 socket U10 is to be used, the RS 232 IC in the socket iust to the Ieft of it, in U9,
nust be renoved. One ol these two communication chips can rcmain in place at a tines
in that the communications
circ it\^ does not confict trith the memory locations.
Tr{E CLOCK rCS (T SOCKET U6l
The two 8-pin Dallas Semiconductor clock ICs are interchangeable, and each of them
goes into the existing empty socket U6. The DS 1302 is the successor to the DS1202.
The NJU6355 also goes jnto socket U6, but it is not pin-for-pjn compatible with the
Dallas Semiconduclor chips. Fortunately, too needs |o have its crystal between pins
il
2 and 3. and its other lines can share the connections to t]rc PIC 16F877A.