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Semiconductor Group
52
On-Chip Peripheral Components
Figure 7-10
Special Function Register ADCON (Address 0D8H)
Using timer 1 to generate baud rates:
Timer 1 can be used for generating baud rates in mode 1 and 3 of the serial channel. Then the baud
rate is determined by the timer 1 overflow rate and the value of SMOD as follows:
The timer 1 interrupt is usually disabled in this application. The timer itself can be configured for
either "timer" or "counter" operation, and in any of its operating modes. In the most typical
applications, it is configured for "timer" operation in the auto-reload mode (high nibble of
TMOD = 0010B). In the case, the baud rate is given by the formula:
One can achieve very low baud rates with timer 1 by leaving the timer 1 interrupt enabled,
configuring the timer to run as 16-bit timer (high nibble of TMOD = 0001B), and using the timer 1
interrupt for a 16-bit software reload.
Table 7-4 lists various commonly used baud rates and shows how they can be obtained from
timer 1.
Bit
Function
BD
Baud rate enable.
When set, the baud rate in modes 1 and 3 of serial interface is taken from
a dedicated prescaler. Standard baud rates 4800 and 9600 baud at
12-MHz oscillator frequency can be achieved.
BD
CLK
ADEX
BSY
ADM
MX2
MX1
MX0
0D8H
ADCON
These bits are not used in controlling serial interface.
0DFH 0DEH 0DDH 0DCH 0DBH 0DAH 0D9H 0D8H
Mode 1, 3 baud rate =
(Timer 1 OV-rate)
32
2
SMOD
x
Mode 1, 3 baud rate =
32 x 12 x (256 – (TH1))
2
SMOD
x oscillator frequency
*
Summary of Contents for SAB 80515 Series
Page 9: ...Semiconductor Group 9 Introduction Figure 1 2 Block Diagram ...
Page 12: ...Semiconductor Group 12 Fundamental Structure Figure 2 1 Detailed Block Diagram ...
Page 18: ...Semiconductor Group 18 Central Processing Unit Figure 3 1 Fetch Execute Sequence ...
Page 73: ...Semiconductor Group 73 On Chip Peripheral Components Figure 7 25 A D Converter Block Diagram ...
Page 83: ...Semiconductor Group 83 On Chip Peripheral Components Figure 7 33 a Timer 2 Block Diagram ...
Page 215: ...Device Specifications Semiconductor Group 215 ...
Page 217: ...Device Specifications Semiconductor Group 217 Pin Configuration P LCC 68 ...
Page 219: ...Device Specifications Semiconductor Group 219 Logic Symbol ...
Page 226: ...Device Specifications Semiconductor Group 226 Figure 1 Block Diagram ...
Page 229: ...Device Specifications Semiconductor Group 229 Figure 2 Memory Address Spaces ...
Page 239: ...Device Specifications Semiconductor Group 239 Figure 4 Block Diagram of the A D Converter ...
Page 241: ...Device Specifications Semiconductor Group 241 Figure 5 Interrupt Request Sources ...
Page 242: ...Device Specifications Semiconductor Group 242 Figure 6 Interrupt Priority Level Structure ...