SM39A16M1
8-Bit Micro-controller
16KB with ISP Flash
& 1K+256B RAM embedded
14. IIC function
The IIC module uses the SCL (clock) and the SDA (data) line to communicate with external IIC interface. Its speed can
be selected to 400Kbps (maximum) by software setting the IICBR [2:0] control bit. The IIC module provided 2 interrupts
(RXIF, TXIF). It will generate START, repeated START and STOP signals automatically in master mode and can
detects START, repeated START and STOP signals in slave mode. The maximum communication length and the
number of devices that can be connected are limited by a maximum bus capacitance of 400pF.
The interrupt vector is 6Bh.
Mnemonic
Description
IIC control
Dir.
Bit 7
Bit 6
Bit 5
Bit 4
Bit 3
Bit 2
Bit 1
Bit 0
RST
IIC function
AB_E
N
IICCTL
IICS
F9h
F8h
IICEN
-
MSS
MPIF
MAS
LAIF
BF_EN
TXIF
IICBR[2:0]
TXAK
04H
00H
register
RW or
BB
IIC status register
RXIF
RXAK
MATC
H1or
RW1
MATC
H2 or
RW2
IIC Address 1
register
IICA1
IICA2
FAh
FBh
IICA1[7:1]
A0H
60H
IIC Address 2
register
IICA2[7:1]
IIC Read/Write
register
IIC Enaable Bus
Transaction
IICRWD
IICEBT
FCh
FDh
IICRWD[7:0]
00H
00H
FU_EN
-
-
-
-
-
-
Mnemonic: IICCTL
Address: F9h
7
6
MSS
5
MAS
4
3
2
1
0
Reset
04h
IICEN
AB_EN
BF_EN
IICBR[2:0]
IICEN: Enable IIC module
IICEN = 1 is Enable
IICEN = 0 is Disable.
MSS: Master or slave mode select.
MSS = 1 is master mode.
MSS = 0 is slave mode.
*The software must set this bit before setting others register.
MAS: Master address select (master mode only)
MAS = 0 is to use IICA1.
MAS = 1 is to use IICA2.
AB_EN: Arbitration lost enable bit. (Master mode only)
If set AB_EN bit, the hardware will check arbitration lost. Once arbitration lost occurred,
hardware will return to IDLE state. If this bit is cleared, hardware will not care arbitration lost
condition. Set this bit when multi-master and slave connection. Clear this bit when single
master to single slave.
BF_EN: Bus busy enable bit. (Master mode only)
If set BF_EN bit, hardware will not generate a start condition to bus until BF=0. Clear this bit
Specifications subject to change without notice contact your sales representatives for the most recent information.
ISSFD-M069 Ver C SM39A16M1 7/31/2013
- 79 -
SYNCMOS [ SYNCMOS TECHNOLOGIES,INC ]
