P1750AE/SOS
SIGNAL DESCRIPTIONS
CLOCKSANDEXTERNALREQUESTS
Mnemonic
Name
Description
CPUCLK
CPU clock
A single phase input clock signal (0-30 MHz, 40 percent to 60 percent
duty cycle.
TIMERCLK
Timer clock
A 100 kHz input that, after synchronization with CPU CLK provides the
clock for timer A and timer B. If timers are used, the CPU CLK signal
frequency must be > 300 kHz.
RESET
Reset
An active LOW input that initializes the device.
CONREQ
Consolerequest
An active LOW input that initiates console operations after completion of
the current instruction.
INTERRUPTINPUTS
Mnemonic
Name
Description
PWRDNINT
Powerdowninterrupt
An interrupt request input that cannot be masked or disabled. This
signal is active on the positive going edge or the high level, according to
the interrupt mode bit in the configuration register.
USR INT-
Userinterrupt
Interrupt request input signals that are active on the positive going
edge or the high level, according to the interrupt mode bit in the
configurationregister.
0
USR INT
5
IOL INT
I/Olevelinterrupts
Active HIGH interrupt request inputs that can be used to expand the
numberofuserinterrupts.
1
IOL INT
2
FAULTS
Mnemonic
MEM PRT ER
Name
Description
Memoryprotecterror
An active LOW input generated by the MMU or BPU, or both and
sampled by the BUS BUSY signal into the Fault Register (bit 0 CPU bus
cycle, bit 1 if non-CPU bus cycle).
MEM PAR ER
EXTADRER
Memoryparityerror
An active LOW input sampled by the BUS BUSY signal into bit 2 of the
faultregister.
Externaladdress
error
An active LOW input sampled by the BUS BUSY signal into the Fault
register (bit 5 or 8), depending on the cycle (memory or I/O).
SYSFLT
SYSFLT
System fault ,
Asynchronous, positive edge-sensitive inputs that set bit 7 (SYSFLT )
0
0
1
0
System fault ,
or bits 13 and 15 (SYSFLT ) in the Fault register.
1
1
ERRORCONTROL
Mnemonic
Name
Description
UNRCVER
Unrecoverableerror
An active HIGH output that indicates the occurrence of an error classified
asunrecoverable.
MAJ ER
Majorerror
An active HIGH output that indicates the occurrence of an error classified
as major.
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PYRAMID [ PYRAMID SEMICONDUCTOR CORPORATION ]
