MC9S12E128CPVE Freescale Semiconductor, MC9S12E128CPVE Datasheet - Page 319

• Manufacturer Part Number: MC9S12E128CPVE
• Description: IC MCU 128K FLASH 25MHZ 112-LQFP
• Manufacturer: Freescale Semiconductor
• Series: HCS12r

Specifications of MC9S12E128CPVE

• Core Processor: HCS12
• Core Size: 16-Bit
• Speed: 25MHz
• Connectivity: EBI/EMI, I²C, SCI, SPI
• Peripherals: POR, PWM, WDT
• Number Of I /o: 91
• Program Memory Size: 128KB (128K x 8)
• Program Memory Type: FLASH
• Ram Size: 8K x 8
• Voltage - Supply (vcc/vdd): 2.35 V ~ 2.75 V
• Data Converters: A/D 16x10b; D/A 2x8b
• Oscillator Type: Internal
• Operating Temperature: -40°C ~ 85°C
• Package / Case: 112-LQFP
• Processor Series: S12E
• Core: HCS12
• Data Bus Width: 16 bit
• Data Ram Size: 8 KB
• Interface Type: SCI/SPI
• Maximum Clock Frequency: 25 MHz
• Number Of Programmable I/os: 92
• Number Of Timers: 12
• Operating Supply Voltage: 3.135 V to 5.5 V
• Maximum Operating Temperature: + 85 C
• Mounting Style: SMD/SMT
• 3rd Party Development Tools: EWHCS12
• Minimum Operating Temperature: - 40 C
• On-chip Adc: 16-ch x 10-bit
• On-chip Dac: 2-ch x 8-bit
• Controller Family/series: HCS12/S12X
• No. Of I/o's: 90
• Ram Memory Size: 8KB
• Cpu Speed: 25MHz
• No. Of Timers: 4
• Embedded Interface Type: I2C, SCI, SPI
• Rohs Compliant: Yes
• For Use With: M68EVB912E128 - BOARD EVAL FOR MC9S12E128/64
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Eeprom Size: -
• Lead Free Status / Rohs Status: Lead free / RoHS Compliant

10.7.1.4
A data transfer ends with a STOP signal generated by the 'master' device. A master transmitter can simply
generate a STOP signal after all the data has been transmitted. The following is an example showing how
a stop condition is generated by a master transmitter.
If a master receiver wants to terminate a data transfer, it must inform the slave transmitter by not
acknowledging the last byte of data which can be done by setting the transmit acknowledge bit (TXAK)
before reading the 2nd last byte of data. Before reading the last byte of data, a STOP signal must be
generated first. The following is an example showing how a STOP signal is generated by a master receiver.
10.7.1.5
At the end of data transfer, if the master continues to want to communicate on the bus, it can generate
another START signal followed by another slave address without first generating a STOP signal. A
program example is as shown.
10.7.1.6
In the slave interrupt service routine, the module addressed as slave bit (IAAS) should be tested to check
if a calling of its own address has just been received. If IAAS is set, software should set the transmit/receive
mode select bit (Tx/Rx bit of IBCR) according to the R/W command bit (SRW). Writing to the IBCR
clears the IAAS automatically. Note that the only time IAAS is read as set is from the interrupt at the end
of the address cycle where an address match occurred, interrupts resulting from subsequent data transfers
will have IAAS cleared. A data transfer may now be initiated by writing information to IBDR, for slave
transmits, or dummy reading from IBDR, in slave receive mode. The slave will drive SCL low in-between
byte transfers, SCL is released when the IBDR is accessed in the required mode.
Freescale Semiconductor
MASTX
END
EMASTX
MASR
LAMAR
ENMASR
NXMAR
RESTART
DEC
BEQ
MOVB
DEC
BNE
BSET
BRA
BCLR
MOVB
RTI
Generation of STOP
Generation of Repeated START
BSET
MOVB
Slave Mode
TST
BEQ
BRSET
MOVB
DEC
BRA
BCLR
RTI
TXCNT
END
IBSR,#$01,END
DATABUF,IBDR
TXCNT
EMASTX
IBCR,#$20
RXCNT
ENMASR
RXCNT,D1
D1
NXMAR
IBCR,#$08
NXMAR
IBCR,#$20
IBDR,RXBUF
IBCR,#$04
CALLING,IBDR
MC9S12E128 Data Sheet, Rev. 1.07
;DECREASE THE RXCNT
;LAST BYTE TO BE READ
;CHECK SECOND LAST BYTE
;TO BE READ
;NOT LAST OR SECOND LAST
;SECOND LAST, DISABLE ACK
;TRANSMITTING
;LAST ONE, GENERATE ‘STOP’ SIGNAL
;READ DATA AND STORE
;ANOTHER START (RESTART)
;TRANSMIT THE CALLING ADDRESS;D0=R/W
;GET VALUE FROM THE TRANSMITING COUNTER
;END IF NO MORE DATA
;END IF NO ACK
;TRANSMIT NEXT BYTE OF DATA
;DECREASE THE TXCNT
;EXIT
;GENERATE A STOP CONDITION
;RETURN FROM INTERRUPT
Chapter 10 Inter-Integrated Circuit (IICV2)
319