SDA5250 Datasheet, PDF (64/143 Pages) Siemens Semiconductor Group – TVTEXT 8-Bit Microcontroller

SDA 525x
Table 15
Interrupt Source
External Request 0
Internal Timer/Counter 0
External Request 1
Internal Timer/Counter 1
Serial Interface
Teletext Sync Signals
Analog Digital Converter
Request Flag
IE0
TF0
IE1
TF1
RI/TI
DVIRST
DHIRST
EVENST
LIN24ST
AVIRST
AHIRST
IADC
Bit Location
TCON.1
TCON.5
TCON.3
TCON.7
SCON.0/.1
TTXSIR.2
TTXSIR.0
ACQSIR.6
ACQSIR.4
ACQSIR.2
ACQSIR.0
ADCON.5
The timer 0 and timer 1 interrupts are generated by TF0 and TF1, which are set by a
rollover in their respective timer/counter register, except for timer 0 in mode 3.
The serial interface interrupt (receive or transmit) is generated when flag RI or TI is set.
RI or TI will be set, when a byte has been received or transmitted over the serial port.
For details see Chapter “More about Mode 0” on page 95, Chapter “More about
Mode 1” on page 95 and Chapter “More about Modes 2 and 3” on page 96.
The teletext sync signal interrupt is generated by setting and enabling at least one of six
possible signal sources: two signals from the display clock system (V and H) and 4
signals from the acquisition clock system (start of even field, start of ACQ- line 24 in each
field, V and H) as shown in Figure 22. The teletext sync signal interrupt is synchronous
to the respective acquisition or display clock system. Thus clock synchronous software
timers can be realized.
The analog digital converter interrupt is generated on completion of the analog digital
conversion.
Within the IE-register there are eight addressable flags. Seven flags enable/disable the
seven interrupt sources when set/cleared. Setting/clearing the eighth flag permits a
global enable/disable of all enabled interrupt requests.
All the bits that generate interrupts can be set or cleared by software, with the same
result as though they had been set or cleared by hardware. That is, interrupts can be
generated or pending interrupt requests can be cancelled by software.
Semiconductor Group
64
1998-04-08