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Data Sheet
51
Rev. 1.0, 2005-06-02
OctalLIU
TM
PEF 22508 E
Functional Description
Masked Interrupts Visible in Status Registers
The “Global” Interrupt Status register (GIS) indicates those interrupt status registers with active interrupt
indications (bits GIS.ISR(7:0)).
An additional interrupt mode can be selected per port via bit GCR.VIS (GCR). In this mode, masked interrupt
status bits neither generate an interrupt on pin INT nor are they visible in GIS, but are displayed in the
corresponding interrupt status registers ISR(1:4), ISR6 and ISR7.
PLL Interrupt Status Register
The bit n (n = 1 to 8) of the register CIS pointers an interrupt on channel n.
The Global Interrupt Status register GIS2 indicates the lock status of the (global) PLL. Masking can be done
by the register GIMR.
An additional interrupt mode can be selected per port via bit IPC.VISPLL (IPC) where the masked interrupt
status bit GIS2.PLLLS does not generate an interrupt on pin INT, but is displayed in the corresponding
interrupt status register bit GIS2.PLLLC.
The additional interrupt mode is useful when some interrupt status bits are to be polled in the individual interrupt
status registers.
Note:
1. In the visible mode, all active interrupt status bits, whether the corresponding actual interrupt is masked or not,
are reset when the interrupt status register is read. Thus, when polling of some interrupt status bits is desired,
care must be taken that unmasked interrupts are not lost in the process.
2. All unmasked interrupt statuses are treated as before.
Please note that whenever polling is used, all interrupt status registers concerned have to be polled individually
(no “hierarchical” polling possible), since GIS only contains information on actually generated, i.e. unmasked
interrupts.
3.5.4
Boundary Scan Interface
In the OctalLIU
TM a Test Access Port (TAP) controller is implemented. The essential part of the TAP is a finite state
machine (16 states) controlling the different operational modes of the boundary scan. Both, TAP controller and
boundary scan, meet the requirements given by the JTAG standard IEEE 1149.1-2001. Figure 15 gives an
overview, Figure 41 shows the timing diagram and Table 52 gives the appropriate values of the timing
parameters.
Table 9
Interrupt Modes
GCR.VIS; IPC.VISPLL
Appropriate Mask bit
Interrupt active
Visibility in ISR(1:4),
ISR(6:7) and GIS2
0
yes
0
1
no
1
0
yes
1
no
yes