PIC12F1822 MICROCHIP [Microchip Technology], PIC12F1822 Datasheet - Page 273

• Manufacturer Part Number: PIC12F1822
• Description: 8/14-Pin Flash Microcontrollers with nanoWatt XLP Technology
• Manufacturer: MICROCHIP [Microchip Technology]

24.7
The MSSP1 module has a Baud Rate Generator avail-
able for clock generation in both I
modes. The Baud Rate Generator (BRG) reload value
is placed in the SSP1ADD register (Register 24-6).
When a write occurs to SSP1BUF, the Baud Rate Gen-
erator will automatically begin counting down.
Once the given operation is complete, the internal clock
will automatically stop counting and the clock pin will
remain in its last state.
An internal signal “Reload” in Figure 24-39 triggers the
value from SSP1ADD to be loaded into the BRG
counter. This occurs twice for each oscillation of the
FIGURE 24-40:
TABLE 24-4:
 2010 Microchip Technology Inc.
Note 1:
Note: Values of 0x00, 0x01 and 0x02 are not valid
BAUD RATE GENERATOR
for SSP1ADD when used as a Baud Rate
Generator for I
limitation.
32 MHz
32 MHz
32 MHz
16 MHz
16 MHz
16 MHz
4 MHz
The I
100 kHz) in all details, but may be used with care where higher rates are required by the application.
F
OSC
2
C interface does not conform to the 400 kHz I
MSSP1 CLOCK RATE W/BRG
BAUD RATE GENERATOR BLOCK DIAGRAM
2
C. This is an implementation
SSP1M<3:0>
SCL
2
C and SPI Master
8 MHz
8 MHz
8 MHz
4 MHz
4 MHz
4 MHz
1 MHz
SSP1M<3:0>
F
CY
PIC12F/LF1822/16F/LF1823
Control
Reload
SSP1CLK
Preliminary
Reload
module clock line. The logic dictating when the reload
signal is asserted depends on the mode the MSSP1 is
being operated in.
Table 24-4 demonstrates clock rates based on
instruction cycles and the BRG value loaded into
SSP1ADD.
EQUATION 24-1:
2
C specification (which applies to rates greater than
BRG Down Counter
SSP1ADD<7:0>
BRG Value
0Ch
4Fh
13h
19h
09h
27h
09h
F
CLOCK
=
-------------------------------------------------

SSPxADD
F
OSC
(2 Rollovers of BRG)
/2
F
OSC
400 kHz
400 kHz
DS41413A-page 273
308 kHz
100 kHz
308 kHz
100 kHz
100 kHz
F
+
CLOCK
1
 4  
(1)
(1)