PIC18F242 MICROCHIP [Microchip Technology], PIC18F242 Datasheet - Page 154

• Manufacturer Part Number: PIC18F242
• Description: 28/40-pin High Performance, Enhanced FLASH Microcontrollers with 10-Bit A/D
• Manufacturer: MICROCHIP [Microchip Technology]

PIC18FXX2
15.4.7.1
Clock arbitration occurs when the master, during any
receive, transmit or Repeated START/STOP condition,
de-asserts the SCL pin (SCL allowed to float high).
When the SCL pin is allowed to float high, the baud rate
generator (BRG) is suspended from counting until the
SCL pin is actually sampled high. When the SCL pin is
FIGURE 15-18:
DS39564C-page 152
Clock Arbitration
SDA
SCL
BRG
Value
BRG
Reload
BAUD RATE GENERATOR TIMING WITH CLOCK ARBITRATION
03h
DX
SCL de-asserted but slave holds
SCL low (clock arbitration)
02h
SCL is sampled high, reload takes
place and BRG starts its count.
01h
BRG decrements on
Q2 and Q4 cycles
00h (hold off)
DX-1
sampled high, the baud rate generator is reloaded with
the contents of SSPADD<6:0> 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 15-18).
SCL allowed to transition high
03h
© 2006 Microchip Technology Inc.
02h