RS_Telecom IP
RM0082
782/844
Doc ID 018672 Rev 1
34.4.12
General purpose GPIOs G8 and G10
●
G8(7:0) and G10(9:0) are a set of eighteen general purpose GPIO provided primarily
for SLIC management.
●
G10(7:0) have an added capability of generating an interrupt on change of value or
persistence of change similar to GPIO_IT bus.
Selection of source of interrupt generation between G10(7:0) and IT(7:0) is explained in
programmer's model (please refer to
Table 711: IT_GEN register (Offset 0x24)
)
34.4.13 IT
bus
●
IT bus is an 8 bit input bus that is supervised.
●
When a change is detected on this bus it can generate the ITch interrupt.
●
It can be important to check that this change persists for more than a determined
persistency time (as programmed in
Table 714: PERS_time register (Offset 0x30)
)
before generating an interrupt. The IT interrupt is then generated.
The purpose of such an interface is to supervise the hook detection of up to 8 SLICs.
Alternatively, it can be used to debounce a switch or simply generate an interrupt when a
signal toggles.
Persistency time is based on TDM clock. The number of clocks to be used for persistency is
programmable. The signal is latched two times and the two latched signals compared. If
they are different the ITch interrupt can be generated if programmed so. It is also possible to
read both the latch register. If a line is programmed to generate an interrupt on a persistent
change, the data is latched after the persistency time and interrupt ITp is generated. This
latched data can also be read.
Figure 103. IT bus change and persistency supervision
34.5 Programmer’s
model
This section describes the programmer’s model.
PERS_TIME register
TDM CLK
ITp
ITch
IT bus(8)
GPIOt
GPIOtt
Pers_DATA
Latch
Change supervision
Peralatency supervision