AT89C5132 Atmel Corporation, AT89C5132 Datasheet - Page 113

• Manufacturer Part Number: AT89C5132
• Manufacturer: Atmel Corporation

Specifications of AT89C5132

• Flash (kbytes): 64 Kbytes
• Max. Operating Frequency: 20 MHz
• Cpu: 8051-12C
• Max I/o Pins: 44
• Usb Transceiver: 1
• Usb Speed: Full Speed
• Usb Interface: Device
• Spi: 1
• Uart: 1
• Adc Channels: 2
• Adc Resolution (bits): 10
• Adc Speed (ksps): 22.7
• Sram (kbytes): 2.25
• Self Program Memory: API
• Operating Voltage (vcc): 2.7 to 3.6
• Timers: 2
• Isp: UART/USB
• Watchdog: Yes

Notes:
18.4.5
4173E–USB–09/07
1. These frequencies are achieved in X1 mode, F
2. These frequencies are achieved in X2 mode, F
Baud Rate Selection
(Mode 2)
Figure 18-13. Baud Rate Formulas (Modes 1 and 3)
Table 90. Baud Rate Generator Configuration
In mode 2, the baud rate can only be programmed to two fixed values: 1/16 or 1/32 of the periph-
eral clock frequency.
As shown in Figure 18-14 the selection is done using SMOD1 bit in PCON register.
Figure 18-15 gives the baud rate calculation formula depending on the selection.
115200
115200
57600
38400
19200
57600
38400
19200
Baud
Baud
Rate
9600
4800
Rate
9600
4800
Baud_Rate=
BRL= 256 -
SPD
SPD
1
1
1
1
1
1
1
1
1
-
-
-
a. IBRG Formula
F
F
SMOD
SMOD
6
6
PER
PER
(1-SPD)
(1-SPD)
1
1
1
1
1
1
1
1
1
1
1
-
-
-
= 12 MHz
= 6 MHz
2
2
SMOD1
SMOD1
⋅ 32 ⋅ (256 -BRL)
⋅ 32 ⋅ Baud_Rate
BRL
BRL
246
236
217
178
243
236
217
178
100
-
-
-
PER
PER
⋅ F
⋅ F
(1)
(2)
PER
PER
= F
= F
Error
Error
2.34
2.34
0.16
0.16
0.16
2.34
0.16
0.16
0.16
OSC
OSC
%
%
-
-
-
.
÷ 2.
SPD
SPD
1
1
1
1
1
1
1
1
1
1
1
-
F
F
SMOD
SMOD
PER
PER
1
1
1
1
1
1
1
1
1
1
1
1
1
-
= 16 MHz
= 8 MHz
BRL
BRL
247
243
230
204
152
247
239
230
204
152
48
-
(1)
(2)
Baud_Rate=
Error
Error
3.55
0.16
0.16
0.16
0.16
3.55
2.12
0.16
0.16
0.16
0.16
TH1= 256 -
%
%
-
b. T1 Formula
SPD
SPD
1
1
1
1
1
1
1
1
1
1
1
-
6 ⋅ 32 ⋅ (256 -TH1)
192 ⋅ Baud_Rate
AT89C5132
2
F
F
2
SMOD
SMOD
SMOD1
SMOD1
PER
PER
1
1
1
1
1
1
1
1
1
1
1
1
0
-
= 10 MHz
= 20 MHz
⋅ F
⋅ F
PER
PER
BRL
BRL
245
240
223
191
126
245
234
223
191
126
126
-
(1)
(2)
Error
Error
1.36
1.73
1.36
0.16
0.16
1.36
1.36
1.36
0.16
0.16
0.16
%
%
-
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