C505_9708 SIEMENS [Siemens Semiconductor Group], C505_9708 Datasheet - Page 171

• Manufacturer Part Number: C505_9708
• Description: 8-Bit CMOS Microcontroller
• Manufacturer: SIEMENS [Siemens Semiconductor Group]

6.5.5 A/D Converter Analog Input Selection
The analog inputs are located at port 1. The corresponding pins have a port structure, which allows
to use them either as digital I/O pins or as analog inputs (see section 6.1.3.2). The analog input
function of these digital/analog port lines are selected via the register P1ANA. This register lies in
the mapped SFR area and can be accessed when bit RMAP in SFR SYSCON is set when writing
to its address (90 H ). If a specific bit location of P1ANA is set, the corresponding port line is
configured as a digital input. With a 0 in the bit location the port line operates as analog port.
Special Function Registers P1ANA (Address 90 H )
Bit
EAN7 - EAN0
Semiconductor Group
Bit No. MSB
90 H
EAN7
7
Function
Enable analog port 1 inputs
If EANx (x = 7-0) is cleared, port pin P1.x is enabled for operation as an
analog input. If EANx is set, port pin P1.x is enabled for digital I/O function
(default after reset).
EAN6
6
EAN5
5
EAN4
4
6-109
EAN3
3
On-Chip Peripheral Components
EAN2
2
EAN1
1
EAN0
LSB
0
Reset Value : FF H
C505 / C505C
P1ANA
1997-08-01