EM78M612
Universal Serial Bus Microcontroller Series
IOCA (Operation Mode Control Register) Default Value: (0B_1100_0000)
7
6
5
0
4
0
3
0
2
0
1
PS/2
0
USB
Dual_Frq.1
Dual_Frq.0
IOCA [0,1] These two bits are used to select the operation mode. EM78M612 can
auto-detect the type of port device being attached. After identifying the port, the
firmware will set these two bits to enter into a proper operation mode. The
definition of these two control registers is described in the table below.
IOCA[1]
IOCA[0]
Operation Mode
Detect Mode
USB Mode
PS/2 Mode
USB Test Mode
0
0
1
1
0
1
0
1
IOCA [2~5] Undefined registers. The default value is 0.
IOCA [6,7] Select the operation frequency in Dual Clock mode. Four frequencies are
available and can be chosen as Dual Clock mode for running the MCU
program.
Dual_Frq.1
Dual_Frq.0
Frequency
0
0
1
1
0
1
0
1
500Hz
4kHz
32kHz
256kHz
IOCB (Port 6 Pull-Low Control Register) Default Value: (0B_0000_0000)
7
6
5
4
3
2
1
0
-
PL67
PL66
PL65
PL64
PL63
PL62
PL61
IOCB [0~7] Select whether the 15K Ohm pull-low resistor of Port 6 individual pin is
connected or not.
1: Enable the pull-low function.
0: Disable the pull-low function.
P60 without Pull low Resistor.
IOCC (Port 6 Pull-High Control Register) Default Value: (0B_0000_0000)
7
6
5
4
3
2
1
0
-
PH67
PH66
PH65
PH64
PH63
PH62
PH61
IOCC [0~7] Select whether the 200K Ohm pull-high resistor of Port 6 individual pin is
connected or not.
This specification may change without further notice.
2004/4/28 V1.1
21
ELAN [ ELAN MICROELECTRONICS CORP ]
