EM78P5840N/41N/42N
8-Bit Microcontrollers
7.2.8 R7 (Port 7 I/O Data, ADC, PWM Duty Cycle)
Page 0 (Port 7 I/O Data Register)
Bit 7
Bit 6
Bit 5
Bit 4
Bit 3
Bit 2
Bit 1
Bit 0
-
-
P76
R/W
P75
R/W
P74
R/W
P73
R/W
-
-
P71
R
P70
R/W
Bit 0 (P70): Port 70 is a multi-function pin. In Crystal mode, set P70S in code option to
define Port 70 as a general purpose I/O or PLLC. Do not enable the PLL
function if Port 70 is defined as an I/O. In IRC or ERIC mode, this pin (Port
70) is defined as general purpose I/O and P70S will be ignored. P70 is Port
70 I/O data register and the IOC7 register can be used to set each bit either
as input or output.
Bit1 (P71): Port 71 is shared with the /RESET pin. Set the code option for P71S and
define Port 71 as an input pin or /RESET pin. This register is a read-only bit.
P71 does not does not have an internal pull high function. If you want to
use the interrupt at P71, external pull high is necessary.
Bit 2 & Bit 7 (undefined): These bits are not used
Bit 3 ~ Bit 6 (P73 ~ P76): 4-bit Port 7 I/O data register. The IOC register can be used
to set each bit either as input or output.
Page 1 (ADC Resolution Selection Bit and ADC MSB Output Data)
Bit 7
Bit 6
Bit 5
AD9
R
Bit 4
AD8
R
Bit 3
Bit 2
ADRES
R/W-0
Bit 1
0
Bit 0
0
-
-
-
-
-
-
R-0
R-0
Bit 0 ~ Bit 1 (undefined): These two bits are not used. However, these bits must be
cleared to “0” to avoid possible error.
Bit 2 (ADRES): Resolution selection for ADC
"0" : ADC is 8-bit resolution. When 8-bit resolution is selected, the most
significant (MSB) 8-bit data output of the internal 10-bit ADC will be
latched and mapped to RB PAGE1 only (see Section 7.2.12). Hence,
R7 PAGE1 Bits 4 ~5 are not implemented.
"1" : ADC is 10-bit resolution. When 10-bit resolution is selected, the 10-bit
data output of the internal 10-bit ADC will be mapped to RB PAGE1 (see
Section 7.2.12), plus R7 PAGE1 Bits 4 ~5 to meet the 10 bits
requirement.
Bit 3 (undefined): This bit is not used
Bit 4 ~ Bit 5 (AD8 ~ AD9): The most significant 2 bits of the 10-bit ADC conversion
output data. Combine these two bits with the RB PAGE1 into a complete
10-bit ADC conversion output data.
Bit 6 ~ Bit 7 (undefined): These bits are not used
12 •
Product Specification (V1.0) 04.25.2006
(This specification is subject to change without further notice)
ELAN [ ELAN MICROELECTRONICS CORP ]
