
421
CHAPTER 21 400 kHz I
2
C INTERFACE
A sample flow is given below.
*
: When "arbitration lost" is detected, the MSS bit is set to "1" and then the AL bit is set to
"1" without fail after the time for three-bit data transmission at the I
2
C transfer frequency.
- Example of occurrence for an interrupt (INT bit = 1) upon detection of "AL bit = 1"
When an instruction which generates a start condition is executed (setting the MSS bit to 1)
with "bus busy" detected (BB bit = 1) and arbitration is lost, the INT bit interrupt occurs upon
detection of "AL bit = 1".
Figure 21.2-5 Diagram of Timing at which an Interrupt Upon Detection of " AL Bit = 1 " Occurs
Master mode setting
Set the MSS bit in the bus control register (IBCR) to "1".
Wait
*
for the time of three-bit data transmission at the I
2
C
transfer frequency set in the clock control register (ICCR).
BB bit = 0 and AL bit = 1 ?
NO
Set the EN bit to "0" to initialize I
2
C
YES
to normal process
DAT
ACK
SLAVE ADDRESS
Start Condition
Interrupt in the ninth clock cycle
SCL pin
SDA pin
EN bit
MSS bit
AL bit
BB bit
INT bit
Clearing the AL bit
by soft
w
are
Releasing the SCL by clearing
the INT bit by soft
w
are
Summary of Contents for MB90390 Series
Page 2: ......
Page 4: ......
Page 17: ...xiii APPENDIX D List of Interrupt Vectors 690 INDEX 695 ...
Page 18: ...xiv ...
Page 132: ...104 CHAPTER 5 CLOCKS ...
Page 152: ...124 CHAPTER 6 CLOCK MODULATOR ...
Page 210: ...182 CHAPTER 11 TIME BASE TIMER ...
Page 218: ...190 CHAPTER 12 WATCHDOG TIMER ...
Page 264: ...236 CHAPTER 14 16 BIT RELOAD TIMER WITH EVENT COUNT FUNCTION ...
Page 274: ...246 CHAPTER 15 WATCH TIMER ...
Page 306: ...278 CHAPTER 17 DTP EXTERNAL INTERRUPTS ...
Page 338: ...310 CHAPTER 18 8 10 BIT A D CONVERTER ...
Page 364: ...336 CHAPTER 19 UART0 UART1 ...
Page 398: ...370 CHAPTER 20 UART2 UART3 Figure 20 5 2 ORE Set Timing Receive data RDRF ORE ...
Page 432: ...404 CHAPTER 20 UART2 UART3 ...
Page 482: ...454 CHAPTER 22 SERIAL I O ...
Page 560: ...532 CHAPTER 24 STEPPING MOTOR CONTROLLER ...
Page 582: ...554 CHAPTER 27 ROM MIRRORING MODULE ...
Page 632: ...604 CHAPTER 29 EXAMPLES OF SERIAL PROGRAMMING CONNECTION ...
Page 722: ...694 APPENDIX ...
Page 723: ...695 INDEX The index follows on the next page This is listed in alphabetic order ...
Page 740: ......