int e l 1.3 BAUD RATES AND CRYSTALS The 16 bit auto-reload timer/counter (TIMER2) that is used to generate baud rates for the MCS BASIC- 52 device is capable of generating accurate baud rates with a number of crystals. The following is a list of crystals that will accurately generate 9600 baud on the MCS BASIC-52 device. Additionally, the crystal values on the left hand side of the table will accurately generate 19200 baud.
XTAL RCAP2 RELOAD XTAL RCAP2 RELOAD 3680400 65524 3993600 65523 4300800 65522 4608000 65521 4915200 65520 5222400 65519 5529600 65518 5836800 65517 6144000 65516 6451200 65515 6758400 65514 7065600 65513 7372800 65512 7680000 65511 7987200 65510 8294400 65509 8601600 65508 8908800 65507 9216000 65506 9523200 65505 9830400 65504 10137600 65503 10444800 65502 10752000 65501 11059200 65500 11366400 65499 11673600 65498 11980800 65497 With the crystals listed above. the accuracy of the baud rate generator and the REAL TIME CLOCK will depend ONLY on the absolute accuracy of the crystal.
Note that the baud rate generator for the 8052AH is so accurate that any crystal above 10 MHz will generate 9600 baud to within 1.5% accuracy. - 174 -