PIC18F2221 MICROCHIP [Microchip Technology], PIC18F2221 Datasheet - Page 193

• Manufacturer Part Number: PIC18F2221
• Description: 28/40/44-Pin Enhanced Flash Microcontrollers with 10-Bit A/D and nanoWatt Technology
• Manufacturer: MICROCHIP [Microchip Technology]

17.4.7
In I
reload value is placed in the lower 7 bits of the
SSPADD register (Figure 17-19). When a write occurs
to SSPBUF, the Baud Rate Generator will automatically
begin counting. The BRG counts down to 0 and stops
until another reload has taken place. The BRG count is
decremented twice per instruction cycle (T
Q2 and Q4 clocks. In I
reloaded automatically.
FIGURE 17-19:
TABLE 17-3:
© 2007 Microchip Technology Inc.
Note 1:
2
C Master mode, the Baud Rate Generator (BRG)
40 MHz
40 MHz
40 MHz
16 MHz
16 MHz
16 MHz
4 MHz
4 MHz
4 MHz
Fosc
The I
100 kHz) in all details, but may be used with care where higher rates are required by the application.
BAUD RATE
2
C™ interface does not conform to the 400 kHz I
I
2
C™ CLOCK RATE W/BRG
SSPM3:SSPM0
BAUD RATE GENERATOR BLOCK DIAGRAM
2
C Master mode, the BRG is
10 MHz
10 MHz
10 MHz
4 MHz
4 MHz
4 MHz
1 MHz
1 MHz
1 MHz
SCL
F
CY
SSPM3:SSPM0
CY
) on the
Control
Reload
Preliminary
CLKO
20 MHz
20 MHz
20 MHz
F
8 MHz
8 MHz
8 MHz
2 MHz
2 MHz
2 MHz
CY
* 2
Reload
Once the given operation is complete (i.e., transmis-
sion of the last data bit is followed by ACK), the internal
clock will automatically stop counting and the SCL pin
will remain in its last state.
Table 17-3 demonstrates clock rates based on
instruction cycles and the BRG value loaded into
SSPADD.
BRG Down Counter
PIC18F4321 FAMILY
2
SSPADD<6:0>
C specification (which applies to rates greater than
BRG Value
1Fh
0Ch
18h
63h
09h
27h
02h
09h
00h
F
OSC
/4
(2 Rollovers of BRG)
DS39689E-page 191
400 kHz
400 kHz
333 kHz
312.5 kHz
1 MHz
100 kHz
308 kHz
100 kHz
100 kHz
F
SCL
(1)
(1)
(1)
(1)