EM78M612
Universal Serial Bus Microcontroller Series
R4 (RAM Select Register) Default Value: (0B_0000_0000)
7
6
5
4
3
2
1
0
BK1
BK0
Ad5
Ad4
Ad3
Ad2
Ad1
Ad0
R4 (RAM select register) contains the address of the registers.
R4 [0~5] are used to select registers in 0x00h~0x3Fh. The address 0x00~0x1F is common
space. After 0x1Fh, SRAM is grouped into four banks.
R4 [6,7] are used to select register banks. To select a registers bank, refer to the following
examples and the table below:
(1) R4=00001100 and R4=01001100 point to the same register 0x0Ch. Since
0x0Ch is in the common space, Bit 6 and Bit 7 are meaningless.
(2) R4=10111100 points to the register 0x3C in Bank 2.
R4[7]Bk1
R4[6]Bk0
RAM Bank #
0
0
1
1
0
1
0
1
Bank 0
Bank 1
Bank 2
Bank3
R5 (Data Line I/O Register) Default Value: (0B_0000_0000)
7
-
6
-
5
-
4
-
3
-
2
-
1
0
D- or PS/2 D+ or PS/2
R5 [0]
R5 [1]
D+ line register or PS/2 clock interface register.
D- line register or PS/2 data interface register.
These two bits are BOTH writable and readable when the MCU is operating under PS/2
mode. But under USB Mode, these two bits cannot be accessed.
R5 [2~7] General purpose registers.
R6 (Port 6 I/O Register) Default Value: (0B_0000_0000)
7
6
5
4
3
2
1
0
P67
P66
P65
P64
P63
P62
P61
P60
R7 (Port 7 I/O Register) Default Value: (0B_0000_0000)
7
6
5
4
3
2
1
0
P77
P76
P75
P74
P73
P72
P71
P70
R8 (Port 6 Wake-up Pin Selection Register) Default Value: (0B_1111_1111)
7
6
5
4
3
2
1
0
/Wu87
/wu86
/Wu85
/Wu84
/Wu83
/Wu82
/Wu81
/Wu80
This specification may change without further notice.
2004/4/28 V1.1
12
ELAN [ ELAN MICROELECTRONICS CORP ]
