5.4.27. SP804_Timer component

The SP804_Timer component is a programmer’s view model of the ARM Dual-Timer module. For a detailed description of the behavior of the SP804 timer, see other documentation. See the ARM Dual-Timer Module (SP804) Technical Reference Manual.

Figure 5.49 shows a view of the component in System Canvas.

Figure 5.49. SP804_Timer in System Canvas

SP804_Timer in System Canvas

This component is written in LISA+.


Table 5.88 provides a brief description of the ports. For more information, see the component documentation.

Table 5.88. SP804_Timer ports

NamePort protocolTypeDescription
pvbusPVBusSlaveSlave port for connection to PV bus master/decoder
irq_out0SignalMasterInterrupt signaling
irq_out1SignalMasterInterrupt signaling
clockClockSignalSlaveClock input, typically 1MHz, driving master count rate
timer_en[0]ClockRateControlSlavePort for changing the rate of timer 1
timer_en[1]ClockRateControlSlavePort for changing the rate of timer 2

Additional protocols

The SP804_Timer component has no additional protocols.


The SP804_Timer component has no parameters.


Table 5.89 provides a description of the configuration registers for the SP804_Timer component.

Table 5.89. SP804_Timer registers

Register nameOffsetAccessDescription
Timer1Load0x000read/writeData register
Timer1Value0x004read onlyValue register
Timer1Control0x008read/writeLoad register
Timer1IntClr0x00Cwrite onlyInterrupt clear register
Timer1RIS0x010read onlyRaw interrupt status register
Timer1MIS0x014read onlyMasked interrupt status register
Timer1BGLoad0x018read/writeBackground load register
Timer2Load0x020read/writeData register
Timer2Value0x024read onlyValue register
Timer2Control0x028read/writeLoad register
Timer2IntClr0x02Cwrite onlyInterrupt clear register
Timer2RIS0x030read onlyRaw interrupt status register
Timer2MIS0x034read onlyMasked interrupt status register
Timer2BGLoad0x038read/writeBackground load register

Debug features

The SP804_Timer component has no debug features.

Verification and testing

The SP804_Timer component has been tested as part of the SMLT component.


The SP804_Timer component is not expected to significantly affect the performance of a PV system.

Library dependencies

The SP804_Timer component has no dependencies on external libraries.

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