© Koninklijke Philips Electronics N.V. 2005. All rights reserved.
User manual
Rev. 01 — 15 August 2005
162
Philips Semiconductors
UM10139
Volume 1
Chapter 11: I
2
C interfaces
11.8.14 I
2
C State service routines
This section provides examples of operations that must be performed by various I
2
C state
service routines. This includes:
•
Initialization of the I
2
C block after a Reset.
•
I
2
C Interrupt Service
Fig 37. Simultaneous repeated START conditions from two masters
Fig 38. Forced access to a busy I
2
C-bus
Fig 39. Recovering from a bus obstruction caused by a low level on SDA
SLA
A
W
SLA
S
18H
08H
A
DATA
28H
08H
OTHER MASTER CONTINUES
Other Master sends Repeated
Start earlier
S
Retry
S
P
SDA Line
SCL Line
STA Flag
STO Flag
Time limit
Start condition
SDA Line
SCL Line
(1)
(2)
(1)
(3)
STA Flag
1. Unsuccessful attempt to send a Start condition.
2. SDA Line released.
3. Succcessful attempt to send a Start condition; state 08H is entered.
Start condition