СРС308 Processor Module
CPC308 Programming
C P C 3 0 8 U s e r M a n u a l
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6.3
User LEDs Control: LED1, LED2
LED1 user LED is controlled with the help of the module input/output space register. The
designation and address of that register are given in the table below.
Table 6
-
3: User LED1 Control Register
Address
Bit 7
Bit 6
Bit 5
Bit 4
Bit 3
Bit 2
Bit 1
Bit 0
11BAh
Reserved
Reserved
Reserved
Reserved
Reserved
Reserved
Reserved
LED1
Where:
LED1
– LED1 activation bit (write “1” - LED1 is on, “0” – LED1 is off).
LED2 user light emitting diode is also programmed with the help of the module input/output
register. The designation and address of that register were specified in subsection 6.1 in Table
6-1: WDT1 Watchdog Timer Control Registers. Write
“1”- LED2 is on, “0” – LED2 is off).
It is not allowed to assign any values to the bits designated as "Reserved". This can
disrupt the module functioning.
6.4
Discrete Input/Output Port Programming
The discrete input/output port is realized on the PCA9538 (NXP) input/output port microchip. This
microchip is connected to SMBus and has the following address: E4h.
The microchip has 4 registers to control the port. The designation of these registers is described
below.
Register 0 - Input buffer register
This register is read-only; it reflects the status of the discrete input/output port channels.
Address
Bit 7
Bit 6
Bit 5
Bit 4
Bit 3
Bit 2
Bit 1
Bit 0
00h
Input 7
Input 6
Input 5
Input 4
Input 3
Input 2
Input 1
Input 0
If any bit of this register has been set, the respective port channel has a high level, if the bit has
been reset, the channel level is low.
