Philips Semiconductors
Low power, low price, low pin count (16 pin)
microcontroller with 2 kbyte OTP
Preliminary data
P87LPC761
Table 10. Baud Rates, Timer Values, and CPU Clock Frequencies for SMOD1 = 1
Timer Count
2400
4800
9600
Baud Rate
19.2 k
38.4 k
–1
0.2304
0.4608
0.9216
* 1.8432
* 3.6864
–2
0.4608
0.9216
* 1.8432
* 3.6864
* 7.3728
–3
0.6912
1.3824
2.7648
5.5296
* 11.0592
–4
0.9216
* 1.8432
* 3.6864
* 7.3728
* 14.7456
–5
1.1520
2.3040
4.6080
9.2160
* 18.4320
–6
1.3824
2.7648
5.5296
* 11.0592
–
–7
1.6128
3.2256
6.4512
12.9024
–
–8
* 1.8432
* 3.6864
* 7.3728
* 14.7456
–
–9
2.0736
4.1472
8.2944
16.5888
–
–10
2.3040
4.6080
9.2160
* 18.4320
–
–11
2.5344
5.0688
10.1376
–
–
–12
2.7648
5.5296
* 11.0592
–
–
–13
2.9952
5.9904
11.9808
–
–
–14
3.2256
6.4512
12.9024
–
–
–15
3.4560
6.9120
13.8240
–
–
–16
* 3.6864
* 7.3728
* 14.7456
–
–
–17
3.9168
7.8336
15.6672
–
–
–18
4.1472
8.2944
16.5888
–
–
–19
4.3776
8.7552
17.5104
–
–
–20
4.6080
9.2160
* 18.4320
–
–
–21
4.8384
9.6768
19.3536
–
–
57.6 k
5.5296
* 11.0592
16.5888
–
–
–
–
–
–
–
–
–
–
–
–
–
–
–
–
–
–
115.2 k
* 11.0592
–
–
–
–
–
–
–
–
–
–
–
–
–
–
–
–
–
–
–
–
NOTES TO TABLES 9 AND 10:
1. Tables 9 and 10 apply to UART modes 1 and 3 (variable rate modes), and show CPU clock rates in MHz for standard baud rates from 2400
to 115.2k baud.
2. Table 9 shows timer settings and CPU clock rates with the SMOD1 bit in the PCON register = 0 (the default after reset), while Table 10
reflects the SMOD1 bit = 1.
3. The tables show all potential CPU clock frequencies up to 20 MHz that may be used for baud rates from 9600 baud to 115.2 k baud. Other
CPU clock frequencies that would give only lower baud rates are not shown.
4. Table entries marked with an asterisk (*) indicate standard crystal and ceramic resonator frequencies that may be obtained from many
sources without special ordering.
2002 Mar 07
35