Signal Description
MOTOROLA
M68060 USER’S MANUAL
2-15
2.10.2 MC68060 Processor Clock (CLK)
CLK is the synchronous clock of the MC68060. This signal is used internally to clock or
sequence the internal logic of the MC68060 processor and is qualified with CLKEN to clock
all external bus signals.
Since the MC68060 is designed for static operation, CLK can be gated off to lower power
dissipation (e.g., during low-power stopped states). Refer to
Section 7 Bus Operation
for
more information on low-power stopped states.
2.10.3 Clock Enable (CLKEN)
This input signal is a qualifier for the MC68060 processor clock (CLK) and is provided to sup-
port lower bus frequency MC68060 designs. The internal MC68060 bus interface controller
will sample, assert, negate, or three-state signals (except for BB and TIP which can three-
Table 2-7. PSTx Encoding
Hex
$00
$01
$02
$03
$04
$05
$06
$07
$08
$09
$0A
$0B
$0C
$0D
$0E
$0F
$10
$11
$12
$13
$14
$15
$16
$17
$18
$19
$1A
$1B
$1C
$1D
$1E
$1F
PST4
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
PST3
0
0
0
0
0
0
0
0
1
1
1
1
1
1
1
1
0
0
0
0
0
0
0
0
1
1
1
1
1
1
1
1
PST2
0
0
0
0
1
1
1
1
0
0
0
0
1
1
1
1
0
0
0
0
1
1
1
1
0
0
0
0
1
1
1
1
PST1
0
0
1
1
0
0
1
1
0
0
1
1
0
0
1
1
0
0
1
1
0
0
1
1
0
0
1
1
0
0
1
1
PST0
0
1
0
1
0
1
0
1
0
1
0
1
0
1
0
1
0
1
0
1
0
1
0
1
0
1
0
1
0
1
0
1
Internal Processor Status
Continue Execution in User Mode
Complete 1 Instruction in User Mode
Complete 2 Instructions in User Mode
—
—
—
—
—
Emulator Mode Entry Exception Processing
Complete Not Taken Branch in User Mode
Complete Not Taken Branch Plus 1 Instruction in User Mode
IED Cycle of Branch to Vector, Emulator Entry Exception
—
Complete Taken Branch in User Mode
Complete Taken Branch Plus 1 Instruction in User Mode
Complete Taken Branch Plus 2 Instructions in User Mode
Continue Execution in Supervisor Mode
Complete 1 Instruction in Supervisor Mode
Complete 2 Instructions in Supervisor Mode
—
—
Complete RTE Instruction in Supervisor Mode
Low-Power Stopped State; Waiting for an Interrupt or Reset
MC68060 Is Stopped Waiting for an Interrupt
MC68060 Is Processing an Exception
Complete Not Taken Branch in Supervisor Mode
Complete Not Taken Branch Plus 1 Instruction in Supervisor Mode
IED Cycle of Branch to Vector, Exception Processing
MC68060 Is Halted
Complete Taken Branch in Supervisor Mode
Complete Taken Branch Plus 1 Instruction in Supervisor Mode
Complete Taken Branch Plus 2 Instructions in Supervisor Mode