PIC12F1822 MICROCHIP [Microchip Technology], PIC12F1822 Datasheet - Page 258

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

PIC12F/LF1822/16F/LF1823
24.6.2
Clock arbitration occurs when the master, during any
receive, transmit or Repeated Start/Stop condition,
releases the SCL pin (SCL allowed to float high). When
the SCL pin is allowed to float high, the Baud Rate Gen-
erator (BRG) is suspended from counting until the SCL
pin is actually sampled high. When the SCL pin is sam-
pled high, the Baud Rate Generator is reloaded with
the contents of SSP1ADD<7:0> and begins counting.
This ensures that the SCL high time will always be at
least one BRG rollover count in the event that the clock
is held low by an external device (Figure 24-25).
FIGURE 24-25:
24.6.3
If the user writes the SSP1BUF when a Start, Restart,
Stop, Receive or Transmit sequence is in progress, the
WCOL is set and the contents of the buffer are
unchanged (the write doesn’t occur). Any time the
WCOL bit is set it indicates that an action on SSP1BUF
was attempted while the module was not Idle.
DS41413A-page 258
Note:
CLOCK ARBITRATION
WCOL STATUS FLAG
Because queueing of events is not
allowed, writing to the lower 5 bits of
SSP1CON2 is disabled until the Start
condition is complete.
SDA
SCL
BRG
Value
BRG
Reload
BAUD RATE GENERATOR TIMING WITH CLOCK ARBITRATION
03h
DX
SCL deasserted but slave holds
SCL low (clock arbitration)
02h
SCL is sampled high, reload takes
place and BRG starts its count
01h
Preliminary
BRG decrements on
Q2 and Q4 cycles
00h (hold off)
DX ‚
–
1
SCL allowed to transition high
03h
 2010 Microchip Technology Inc.
02h