Intersil CDP1805ACD Cmos 8-bit microprocessor with on-chip ram and counter/timer Datasheet

CDP1805AC,
CDP1806AC
TM
CMOS 8-Bit Microprocessor with On-Chip RAM†
and Counter/Timer
March 1997
Features
Description
• Instruction Time of 3.2µs, -40oC to +85oC
The CDP1805AC and CDP1806AC are functional and performance enhancements of the CDP1802 CMOS 8-bit register-oriented microprocessor series and are designed for use
in general-purpose applications.
• 123 Instructions - Upwards Software Compatible With
CDP1802
• BCD Arithmetic Instructions
• Low-Power IDLE Mode
• Pin Compatible With CDP1802 Except for Terminal 16
• 64K-Byte Memory Address Capability
• 64 Bytes of On-Chip RAM†
• 16 x 16 Matrix of On-Board Registers
• On-Chip Crystal or RC Controlled Oscillator
• 8-Bit Counter/Timer
The CDP1805AC hardware enhancements include a 64byte RAM and an 8-bit presettable down counter. The
Counter/Timer which generates an internal interrupt request,
can be programmed for use in timebase, event-counting,
and pulse-duration measurement applications. The
Counter/Timer underflow output can also be directed to the
Q output terminal. The CDP1806AC hardware enhancements are identical to the CDP1805AC, except the
CDP1806AC contains no on-chip RAM.
The CDP1805AC and CDP1806AC software enhancements
include 32 more instructions than the CDP1802. The 32 new
software instructions add subroutine call and return capability, enhanced data transfer manipulation, Counter/Timer control, improved interrupt handling, single-instruction loop
counting, and BCD arithmetic.
Upwards software and hardware compatibility is maintained
when substituting a CDP1805AC or CDP1806AC for other
CDP1800-series microprocessors. Pinout is identical except
for the replacement of VCC with ME on the CDP1805AC and
the replacement of VCC with VDD on the CDP1806AC.
n
Ordering Information
CDP1805AC
CDP1805ACE
CDP1805ACQ
CDP1805ACD
CDP1805ACDX
CDP1806AC
TEMPERATURE RANGE
PACKAGE
PKG. NO.
-40oC to +85oC
Plastic DIP
CDP1806ACQ
-40oC to +85oC
PLCC
N44.65
CDP1806ACD
-40oC to +85oC
SBDIP
D40.6
CDP1806ACE
CDP1806ACEX
E40.6
Burn-In
-
Burn-In
† CDP1805AC Only
CAUTION: These devices are sensitive to electrostatic discharge; follow proper IC Handling Procedures.
1-888-INTERSIL or 321-724-7143 | Intersil (and design) is a trademark of Intersil Americas Inc.
Copyright © Intersil Americas Inc. 2002. All Rights Reserved
1
File Number
1370.2
CDP1805AC, CDP1806AC
Pinouts
38 DMA IN
4
37 DMA OUT
SC1
5
36 INTERRUPT
SC0
6
35 MWR
MRD
7
34 TPA
6 5 4 3 2 1 44 43 42 41 40
BUS 7
8
33 TPB
SC0
MRD
BUS 6
9
32 MA7
BUS 7
9
BUS 5 10
31 MA6
BUS 6
10
BUS 4 11
30 MA5
BUS 5
11
BUS 3 12
29 MA4
NC
12
BUS 4
13
14
15
7
8
BUS 2 13
28 MA3
BUS 1 14
27 MA2
BUS 3
BUS 2
BUS 0 15
26 MA1
BUS 1
16
† 16
25 MA0
BUS 0
17
37
36
35
TPB
34
33
32
NC
TPA
MA7
MA6
MA5
MA4
MA3
MA2
MA1
MA0
EF2
EF1
EF3
EF4
NC
21 EF4
VSS
22 EF3
VSS 20
N0
23 EF2
N0 19
MWR
18 19 20 21 22 23 24 25 26 27 28
N1
24 EF1
N1 18
39
38
31
30
29
†
N2
N2 17
INTERRUPT
3
Q
DMA - IN
DMA - OUT
CLEAR
XTAL
39 XTAL
VDD
40 VDD
2
CLOCK
NC
1
WAIT
WAIT
CLOCK
CLEAR
CDP1805AC, CDP1806AC
(PLCC, PACKAGE TYPE Q)
TOP VIEW
SC1
Q
CDP1805AC, CDP1806AC
(PDIP, SBDIP)
TOP VIEW
† ME for CDP1805AC
VDD for CDP1806AC
Schematic
ADDRESS BUS
MA0 - MA7 MRD
IN
CDP1851
PIO
CONTROL
MA0 - MA7
CDP1805AC WITH
RAM, COUNTER/TIMER
CDP1806AC WITH
COUNTER/TIMER
MRD
MWR
TPA
BUS0 - BUS7
BUS0 - BUS7
CDP1824
32 BYTE RAM
(USED WITH
CDP1806AC ONLY)
CDP1833
1K BYTE ROM
MWR
OUT
MA0-MA4
TPA
ME
BUS0 - BUS7
CEO
CS
(CDP1805AC ONLY)
8-BIT DATA BUS
FIGURE 1. TYPICAL CDP1805AC, CDP1806AC SMALL MICROPROCESSOR SYSTEM
2
BUS0-BUS4
BUS 0
BUS 1
BUS 2
BUS 3
BUS 4
BUS 5
BUS 6
BUS 7
CDP1805AC
ONLY
3
D
(8)
B
(8)
ALU
8-BIT
COUNTER/TIMER
COUNTER HOLDING
REGISTER (CH)
64-BYTE
RAM
ME FOR CDP1805AC
VDD FOR CDP1806AC
DF
(1)
CLK
FIGURE 2. BLOCK DIAGRAM FOR CDP1805AC AND CDP1806AC
A
(16)
R(E).1 R(E).0
R(F).1 R(F).0
R(9).1 R(9).0
R(A).1 R(A).0
R(0).1 R(0).0
R(1).1 R(1).0
R(2).1 R(2).0
÷ 32
LATCH
AND
DECODE
T
(8)
CONTROL
I
(4)
TC
INSTRUCTION
DECODE
CLEAR WAIT
P
(4)
CONTROL AND
TIMING LOGIC
CLOCK
LOGIC
DMA
OUT
DMA
IN INT
I/O REQUESTS
X
(4)
INTERRUPT
LOGIC
EF1
EF2
TPA
REGISTER
ARRAY
R
8-BIT BIDIRECTIONAL DATA BUS
INCR/
DECR
MODE
CONTROL
EF1 EF3
EF2 EF4
MA7 MA5 MA3 MA1
MA6 MA4 MA2 MA0
MUX
I/O FLAGS
MEMORY ADDRESS LINES
N
(4)
N0
N1
N2
I/O
COMMANDS
XTAL
SCO
STATE
CODES
SCI
Q LOGIC
TPA
TPB
SYSTEM
TIMING
MWR
MRD
CLOCK
CDP1805AC, CDP1806AC
CDP1805AC, CDP1806AC
Absolute Maximum Ratings
Thermal Information
DC Supply Voltage Range, (VDD)
(All Voltages Referenced to VSS Terminal). . . . . . . . . -0.5V to +7V
Input Voltage Range, All Inputs . . . . . . . . . . . . . -0.5V to VDD +0.5V
DC Input Current, any One Input . . . . . . . . . . . . . . . . . . . . . . . . . ±10mA
Thermal Resistance (Typical, Note 2)
θJA (oC/W)
θJC (oC/W)
PDIP Package . . . . . . . . . . . . . . . . . . .
50
N/A
PLCC Package . . . . . . . . . . . . . . . . . .
46
N/A
SBDIP Package. . . . . . . . . . . . . . . . . .
55
15
Device Dissipation Per Output Transistor
TA = Full Package Temperature Range . . . . . . . . . . . . . . 100mW
Operating Temperature Range (TA)
Package Type D . . . . . . . . . . . . . . . . . . . . . . . . .-55oC to +125oC
Package Type E and Q . . . . . . . . . . . . . . . . . . . . .-40oC to +85oC
Storage Temperature Range (TSTG). . . . . . . . . . . .-65oC to +150oC
Lead Temperature (During Soldering)
At Distance 1/16 ±1/32in (1.59 ± 0.79mm) from case for
10s Max . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . +265oC
Printed Circuit Board Mount: 57mm x 57mm Minimum Area x 1.6mm
Thick G10 Epoxy Glass, or Equivalent.
CAUTION: Stresses above those listed in “Absolute Maximum Ratings” may cause permanent damage to the device. This is a stress only rating and operation
of the device at these or any other conditions above those indicated in the operational sections of this specification is not implied.
Recommended Operating Conditions
TA = Full-Package Temperature Range. For maximum reliability, operating conditions
should be selected so that operation is always within the following ranges.
CDP1805ACD, CDP1805ACE
CDP1806ACD, CDP1806ACE
TEST CONDITIONS
VDD
(V)
PARAMETER
MIN
MAX
UNITS
DC Operating Voltage Range
-
4
6.5
V
Input Voltage Range
-
VSS
VDD
V
Minimum Instruction Time (Note 1)
(fCL = 5MHz)
5
3.2
-
µs
Maximum DMA Transfer Rate
5
-
0.625
Mbyte/s
Maximum Clock Input Frequency,
Load Capacitance (CL) = 50pF
5
DC
5
MHz
Maximum External Counter/Timer Clock
Input Frequency to EF1, EF2
5
DC
2
MHz
NOTES:
1. Equals 2 machine cycles - one Fetch and one Execute operation for all instructions except Long Branch, Long Skip, NOP, and “68” family
instructions, which are more than two cycles.
2. θJA is measured with the component mounted on an evaluation PC board in free air.
Static Electrical Specifications
at TA = -40oC to +85oC, VDD ±5%, Except as Noted
CDP1805ACD, CDP1805ACE
CDP1806ACD, CDP1806ACE
VO
(V)
VIN
(V)
VDD
(V)
MIN
(NOTE 3)
TYP
MAX
UNITS
-
0, 5
5
-
50
200
µA
0.4
0, 5
5
1.6
4
-
mA
0.4
5
5
0.2
0.4
-
mA
4.6
0, 5
5
-1.6
-4
-
mA
4.6
0
5
-0.1
-0.2
-
mA
Output Voltage Low Level, VOL
-
0, 5
5
-
0
0.1
V
Output Voltage High Level, VOH
-
0, 5
5
4.9
5
-
V
PARAMETER
Quiescent Device Current, IDD
Output Low Drive (Sink) Current, (Except XTAL), IOL
XTAL Output, IOL
Output High Drive (Source) Current (Except XTAL, IOH
XTAL, IOH
4
CDP1805AC, CDP1806AC
Static Electrical Specifications
at TA = -40oC to +85oC, VDD ±5%, Except as Noted (Continued)
CDP1805ACD, CDP1805ACE
CDP1806ACD, CDP1806ACE
VO
(V)
VIN
(V)
VDD
(V)
MIN
(NOTE 3)
TYP
MAX
UNITS
Input Low Voltage (BUS0 - BUS7, ME), VIL
0.5, 4.5
-
5
-
-
1.5
V
Input High Voltage (BUS0 - BUS7, ME), VIH
0.5, 4.5
-
5
3.5
-
-
V
Positive Trigger Threshold, VP
0.5, 4.5
-
5
2.2
2.9
3.6
V
Negative Trigger Threshold, VN
0.5, 4.5
-
5
0.9
1.9
2.8
V
Hysteresis, VH
0.5, 4.5
-
5
0.3
0.9
1.6
V
-
0, 5
5
-
±0.1
±5
µA
0, 5
0, 5
5
-
±0.2
±5
µA
Input Capacitance, CIN
-
-
-
-
5
7.5
pF
Output Capacitance, COUT
-
-
-
-
10
15
pF
Run
-
-
5
-
35
50
mW
Idle “00” at M (0000)
-
-
5
-
12
18
mW
PARAMETER
Schmitt Trigger Input Voltage (Except BUS0 - BUS7, ME)
Input Leakage Current, IIN
Three-State Output Leakage Current, IOUT
Total Power Dissipation (Note 4)
Minimum Data Retention Voltage, VDR
VDD = VDR
-
2
2.4
V
Data Retention Current, IDR
VDD = 2.4
-
25
100
µA
NOTES:
3. Typical values are for TA = +25oC and nominal VDD.
4. External clock: f = 5MHz, t R, t F = 10ns; C L = 50pF.
Dynamic Electrical Specifications
at TA = -40o to +85oC; C L = 50pF; Input t R, t F = 10ns; Input Pulse Levels = 0.1V to
V DD -0.1V; V DD = 5V, ±5%.
CDP1805AC CDP1806AC
(NOTE 5)
TYP
MAX
UNITS
Clock to TPA, TPB, tPLH, tPHL
150
275
ns
Clock-to-Memory High-Address Byte, tPLH, tPHL
325
550
ns
Clock-to-Memory Low-Address Byte, tPLH, tPHL
275
450
ns
Clock to MRD, tPLH, tPHL
200
325
ns
Clock to MWR, tPLH, tPHL (See Note 5)
150
275
ns
Clock to (CPU DATA to BUS), tPLH, tPHL
375
625
ns
Clock to State Code, tPLH, tPHL
225
400
ns
Clock to Q, tPLH, tPHL
250
425
ns
Clock to N, tPLH, tPHL
250
425
ns
Clock to Internal RAM Data to BUS, tPLH, tPHL
420
650
ns
PARAMETER
Propagation Delay Times
5
CDP1805AC, CDP1806AC
Dynamic Electrical Specifications
at TA = -40o to +85oC; C L = 50pF; Input t R, t F = 10ns; Input Pulse Levels = 0.1V to
V DD -0.1V; V DD = 5V, ±5%. (Continued)
CDP1805AC CDP1806AC
(NOTE 5)
TYP
MAX
UNITS
Data Bus Input Set-Up, tSU
-100
0
ns
Data Bus Input Hold, tH
125
225
ns
DMA Set-Up, tSU
-75
0
ns
DMA Hold, tH
100
175
ns
ME Set-Up, t
125
320
ns
0
50
ns
Interrupt Set-Up, tSU
-100
0
ns
Interrupt Hold, tH
100
175
ns
WAIT Set-Up, tSU
20
50
ns
EF1-4 Set-Up, tSU
-125
0
ns
EF1 -4 Hold, tH
175
300
ns
CLEAR Pulse Width, tWL
100
175
ns
CLOCK Pulse Width, tW
75
100
ns
PARAMETER
Minimum Set-Up And Hold Times (Note 2)
SU
ME Hold, tH
Minimum Pulse Width Times (Note 6)
NOTES:
5. Typical values are for TA = 25o C and nominal VDD.
6. Maximum limits of minimum characteristics are the values above which all devices function.
Timing Specifications
as a function of T (T = 1/fCLOCK) at TA = -40 to +85oC, VDD = 5V, ±15%
CDP1805AC, CDP1806AC
PARAMETER
TYP
(NOTE 7)
MAX
UNITS
2T-275
2T -175
ns
T/2 -100
T/2 -75
ns
T/2 +75
T/2 +100
ns
T +180
T +240
ns
T +110
T +150
ns
4.5T -440
4.5T -330
ns
High-Order Memory-Address Byte
Set-Up to TPA
MRD to TPA
Time, tSU
Time, tSU
High-Order Memory-Address Byte
Hold after TPA Time, tH
Low-Order Memory-Address Byte
Hold after WR Time, tH
CPU Data to Bus
Hold after WR Time, tH
Required Memory Access Time, tACC
Address to Data
NOTE:
7. Typical values are for TA = +25oC and nominal VDD.
6
CDP1805AC, CDP1806AC
Timing Waveforms For Possible Operating Modes
INTERNAL RAM READ CYCLE
00
10
20
30
40
50
INTERNAL RAM WRITE CYCLE
60
70
00
10
20
30
40
50
60
70
CLOCK
01
11
21
31
41
51
61
71
01
11
21
31
41
51
61
71
TPA
TPB
MEMORY
ADDRESS
HIGH BYTE
LOW BYTE
HIGH BYTE
LOW BYTE
MRD
MWR
†ME
IN
VALID DATA FROM MEMORY
DATA
BUS
VALID DATA FROM CPU
NOTE:
8. ME has a minimum setup and hold time with respect to the beginning of clock 70. For a memory read operation, RAM data will appear on
the data bus during the time ME is active after clock 31. The time shown can be longer, if for instance, a DMA out operation is performed
on internal RAM data, to allow data enough time to be latched into an external device. The internal RAM is automatically deselected at
the end of clock 71 independent of ME.
† For CDP1805AC only.
FIGURE 3. INTERNAL MEMORY OPERATION TIMING WAVEFORMS
EXTERNAL MEMORY READ CYCLE
00
10
20
30
40
50
EXTERNAL MEMORY WRITE CYCLE
60
70
00
10
20
30
40
50
60
70
CLOCK
01
11
21
31
41
51
61
71
01
11
21
31
41
51
TPA
TPB
MEMORY
ADDRESS
HIGH BYTE
LOW BYTE
HIGH BYTE
LOW BYTE
MRD
MWR
†ME IN
(HIGH)
DATA
BUS
DATA LATCHED IN CPU
VALID DATA FROM CPU
NOTE:
† For CDP1805AC only.
FIGURE 4. EXTERNAL MEMORY OPERATION TIMING WAVEFORMS
7
61
71
CDP1805AC, CDP1806AC
tW
CLOCK
00
0
1
01
10
2
11
20
tPLH
3
21
30
4
31
40
5
41
50
6
51
7
60
61
70
0
71
00
01
tPHL
TPA
MEMORY
ADDRESS
MRD
(MEMORY
READ CYCLE)
tPLH
tPLH, tPHL
TPB
tSU
tPLH, tPHL
tPHL
tH
tH
LOW ORDER
ADDRESS BYTE
HIGH ORDER
ADDRESS BYTE
tSU
tPLH
tPHL
tPHL
tPLH
MWR
(MEMORY
WRITE CYCLE)
tPHL
† ME
(MEMORY
ENABLE)
tSU
tSU IS ALLOWABLE
INTERNAL RAM
ACCESS TIME
†† EMS
(EXTERNAL
MEMORY
SELECT)
tH
tPLH
tPHL
tH
tPLH,
tPHL
DATA FROM
CPU TO BUS
DATA FROM
INTERNAL MEMORY
TO BUS (ME = LOW)
tPLH
tPHL
tPLH, tPLH
tPLH,
tPHL
tPLH, tPHL
STATE CODES
tPLH, tPHL
Q
N0, N1, N2
(I/O EXECUTION
CYCLE)
tPHL
tPLH
DATA LATCHED
IN CPU
tSU
tH
DATA FROM
BUS TO CPU
DMA SAMPLED (S1, S2, S3)
DMA REQUEST
INTERRUPT
SAMPLED (S1, S2)
INTERRUPT
REQUEST
tSU
tH
tSU
tH
FLAG LINES
SAMPLED END OF S0
EF1 - EF4
tSU
tSU
tH
tSU
tH
WAIT
tWL
CLEAR
NOTES:
† This Timing Diagram is used to show signal relationships only, and does not represent any specific machine cycle.
† All measurements are referenced to 50% point of the wave forms.
† Shaded areas indicate “don’t care” or undefined state. Multiple transitions may occur during this period.
† For the run (RAM only) mode only.
†† For the run (RAM/ROM) mode only.
FIGURE 5. TIMING WAVEFORMS
8
tH
CDP1805AC, CDP1806AC
Enhanced CDP1805AC and CDP1806AC
Operation
MRD = VDD: Input data from I/O to CPU and memory.
Timing
EF1 to EF4 (4 Flags)
Timing for the CDP1805AC and CDP1806AC is the same as
the CDP1802 microprocessor series, with the following
exceptions:
These inputs enable the I/O controllers to transfer status
information to the processor. The levels can be tested by the
conditional branch instructions. They can be used in conjunction with the INTERRUPT request line to establish interrupt priorities. The flag(s) are sampled at the end of every S0
cycle. EF1 and EF2 are also used for event counting and
pulse width measurement in conjunction with the
Counter/Timer.
MRD = VSS: Output data from Memory to I/O.
• 4.5 Clock Cycles Are Provided for Memory Access Instead
of 5.
• Q Changes 1/2 Clock Cycle Earlier During the SEQ and
REQ Instructions.
• Flag Lines (EF1-EF4) Are Sampled at the End of the S0
Cycle Instead of at the Beginning of the S1 Cycle.
INTERRUPT, DMA-IN, DMA-OUT (3 I/O Requests)
DMA-lN and DMA-OUT are sampled during TPB every S1,
S2, and S3 cycle. INTERRUPT is sampled during TPB every
S1 and S2 cycle.
• Pause Can Only Occur on the Low-To-High Transition of
Either TPA or TPB, Instead of any Negative Clock Transition.
Interrupt Action - X and P are stored in T after executing
current instruction; designator X is set to 2; designator P is
set to 1; interrupt enable (MIE) is reset to 0 (inhibit); and
instruction execution is resumed. The interrupt action
requires one machine cycle (S3).
Special Features
Schmitt triggers are provided on all inputs, except ME and
BUS 0-BUS 7, for maximum immunity from noise and slow
signal transitions. A Schmitt Trigger in the oscillator section
allows operation with an RC or crystal.
DMA Action - Finish executing current instruction; R(0)
points to memory area for data transfer; data is loaded into
or read out of memory; and R(0) is incremented.
The CDP1802 Series LOAD mode is not retained. This
mode (WAIT, CLEAR = 0) is not allowed on the CDP1805AC
and CDP1806AC.
NOTE: In the event of concurrent DMA and INTERRUPT requests,
DMA-IN has priority followed by DMA-OUT and then INTERRUPT.
(The interrupt request is not internally latched and must be held true
after DMA).
A low power mode is provided, which is initiated via the IDLE
instruction. In this mode all external signals, except the oscillator, are stopped on the low-to-high transition of TPB. All
outputs remain in their previous states, MRD is set to a logic
“1”, and the data bus floats. The IDLE mode is exited by a
DMA or INT condition. The INT includes both external interrupts and interrupts generated by the Counter/Timer. The
only restrictions are that the Timer mode, which uses the
TPA ÷ 32 clock source, and the underflow condition of the
Pulse Width Measurement modes are not available to exit
the IDLE mode.
SC0, SC1, (2 State Code Lines)
These outputs indicate that the CPU is: 1) fetching an
instruction, or 2) executing an instruction, or 3) processing a
DMA request, or 4) acknowledging an interrupt request. The
levels of state code are tabulated below. All states are valid
at TPA.
STATE CODE LINES
STATE TYPE
Signal Descriptions
SC1
SC0
S0 (Fetch)
L
L
S1 (Execute)
L
H
S2 (DMA)
H
L
S3 (Interrupt)
H
H
Bus 0 to Bus 7 (Data Bus)
8-Bit bidirectional DATA BUS lines. These lines are used for
transferring data between the memory, the microprocessor,
and I/O devices.
N0 to N2 (I/O) Lines
NOTE: H = VDD, L = VSS.
Activated by an I/O instruction to signal the I/O control logic
of a data transfer between memory and I/O interface. These
lines can be used to issue command codes or device selection codes to the I/O devices. The N-bits are low at all times
except when an I/O instruction is being executed. During this
time their state is the same as the corresponding bits in the
N Register. The direction of data flow is defined in the I/O
instruction by bit N3 (internally) and is indicated by the level
of the MRD Signal:
TPA, TPB (2 Timing Pulses)
Positive pulses that occurrence in each machine cycle (TPB
follows TPA). They are used by I/O controllers to interpret
codes and to time interaction with the data bus. The trailing
edge of TPA is used by the memory system to latch the highorder byte of the multiplexed 16-bit memory address.
9
CDP1805AC, CDP1806AC
MA0 to MA7 (8 Memory Address Lines)
ME (Memory Enable CDP1805AC Only)
In each cycle, the higher-order byte of a 16-bit memory
address appears on the memory address lines MA0-7 first.
Those bits required by the memory system can be strobed
into external address latches by timing pulse TPA. The loworder byte of the 16-bit address appears on the address
lines 1/2 clock after the termination of TPA.
This active low input is used to select or deselect the internal
RAM. It must be active prior to clock 70 for an internal RAM
access to take place. Internal RAM data will appear on the
data bus during the time that ME is active (after clock 31).
Thus, if this data is to be latched into an external device (i.e.,
during an OUTPUT instruction or DMA OUT cycle), ME
should be wide enough to provide enough time for valid data
to be latched. The internal RAM is automatically deselected
after clock 71. ME is ineffective when MRD • MWR = 1.
MWR (Write Pulse)
A negative pulse appearing in a memory-write cycle, after
the address lines have stabilized.
The internal RAM is not internally mask-decoded. Decoding
of the starting address is performed externally, and may
reside in any 64-byte block of memory.
MRD (Read Level)
A low level on MRD indicates a memory read cycle. It can be
used to control three-state outputs from the addressed memory and to indicate the direction of data transfer during an I/O
instruction.
VDD (CDP1806AC Only)
This input replaces the ME signal of the CDP1805AC and
must be connected to the positive power supply.
Q
VDD, VSS, (Power Levels)
Single bit output from the CPU which can be set or reset,
under program control. During SEQ and REQ instruction
execution, Q is set or reset between the trailing edge of TPA
and the leading edge of TPB. The Q line can also be controlled by the Counter/Timer underflow via the Enable Toggle
Q instruction.
VSS is the most negative supply voltage terminal and is normally connected to ground. VDD is the positive supply voltage terminal. All outputs swing from VSS to VDD. The
recommended input voltage swing is from VSS to VDD.
Architecture
The Enable Toggle Q command connects the Q-line flip-flop
to the output of the counter, such that each time the counter
decrements from 01 to its next value, the Q line changes
state. This command is cleared by a LOAD COUNTER
(LDC) instruction with the Counter/Timer stopped, a CPU
reset, or a BRANCH COUNTER INTERRUPT (BCl) instruction with the counter interrupt flip-flop set.
Figure 2 shows a block diagram of the CDP1805AC and
CDP1806AC. The principal feature of this system is a register array (R) consisting of sixteen 16-bit scratchpad registers. Individual registers in the array (R) are designated
(selected) by a 4-bit binary code from one of the 4-bit registers labeled N, P, and X. The contents of any register can be
directed to any one of the following paths:
Clock
1. The external memory (multiplexed, higher-order byte first
on to 8 memory address lines).
Input for externally generated single-phase clock. The maximum clock frequency is 5MHz at VDD = 5V. The clock is
counted down internally to 8 clock pulses per machine cycle.
2. The D register (either of the two bytes can be gated to D).
3. The increment/decrement circuit where it is increased or
decreased by one and stored back in the selected 16-bit
register.
XTAL
Connection to be used with clock input terminal, for an external crystal, if the on-chip oscillator is utilized.
4. To any other 16-bit scratch pad register in the array.
The four paths, depending on the nature of the instruction,
may operate independently or in various combinations in the
same machine cycle.
WAIT, CLEAR (2 Control Lines)
Provide four control modes as listed in the following truth
table:
CLEAR
WAIT
MODE
L
L
Not Allowed
L
H
Reset
H
L
Pause
H
H
Run
Most instructions consist of two 8-clock-pulse machine
cycles. The first cycle is the fetch cycle, and the second, and
more if necessary, are execute cycles. During the fetch cycle
the four bits in the P designator select one of the 16 registers
R(P) as the current program counter. The selected register
R(P) contains the address of the memory location from
which the instruction is to be fetched. When the instruction is
read out from the memory, the higher order 4 bits of the
instruction byte are loaded into the register and the lower
order 4 bits into the N register. The content of the program
counter is automatically incremented by one so that R(P) is
now “pointing” to the next byte in the memory.
10
CDP1805AC, CDP1806AC
Another important use of R as a data pointer supports the
built-in Direct-Memory-Access (DMA) function. When a
DMA-ln or DMA-Out request is received, one machine cycle
is “stolen”. This operation occurs at the end of the execute
machine cycle in the current instruction. Register R(0) is
always used as the data pointer during the DMA operation.
The data is read from (DMA-Out) or written into (DMA-ln) the
memory location pointed to by the R(0) register. At the end
of the transfer, R(0) is incremented by one so that the processor is ready to act upon the next DMA byte transfer
request. This feature in the CDP1805AC and CDP1806AC
architecture saves a substantial amount of logic when fast
exchanges of blocks of data are required, such as with magnetic discs or during CRT-display-refresh cycles.
The X designator selects one of the 16 registers R(X) to
“point” to the memory for an operand (or data) in certain ALU
or I/O operations.
The N designator can perform the following five functions
depending on the type of instruction fetched:
1. Designate one of the 16 registers in R to be acted upon
during register operations.
2. Indicate to the I/O devices a command code or deviceselection code for peripherals.
3. Indicate the specific operation to be executed during the
ALU instructions, types of tests to be performed during
the Branch instructions, or the specific operation required
in a class of miscellaneous instructions.
Data Registers
4. Indicate the value to be loaded into P to designate a new
register to be used as the program counter R(P).
When registers in R are used to store bytes of data, instructions are provided which allow D to receive from or write into
either the higher-order- or lower-order-byte portions of the
register designated by N. By this mechanism (together with
loading by data immediate) program pointer and data pointer
designations are initialized. Also, this technique allows
scratchpad registers in R to be used to hold general data. By
employing increment or decrement instructions, such registers may be used as loop counters. The new RLDl, RLXA,
RSXD, and RNX instructions also allow loading, storing, and
exchanging the full 16-Bit contents of the R registers without
affecting the D register. The new DBNZ instruction allows
decrementing and branching-on-not-zero of any 16-Bit R
register also without affecting the D register.
5. Indicate the value to be loaded into X to designate a new
register to be used as data pointer R(X).
The registers in R can be assigned by a programmer in three
different ways as program counters, as data pointers, or as
scratchpad locations (data registers) to hold two bytes of
data.
Program Counters
Any register can be the main program counter; the address
of the selected register is held in the P designator. Other registers in R can be used as subroutine program counters. By
a single instruction the contents of the P register can be
changed to effect a “call” to subroutine. When interrupts are
being serviced, register R(1) is used as the program counter
for the user's interrupt servicing routine. After reset, and during a DMA operation, R(0) is used as the program counter.
At all other times the register designated as program counter
is at the discretion of the user.
The Q Flip-Flop
An internal flip-flop, Q, can be set or reset by instruction and
can be sensed by conditional branch instructions. It can also
be driven by the underflow output of the counter/timer The
output of Q is also available as a microprocessor output.
REGISTER SUMMARY
Data Pointers
The registers in R may be used as data pointers to indicate a
location in memory. The register designated by X (i.e., R(X))
points to memory for the following instructions (see Table 1):
1. ALU operations.
2. Output instructions.
D
8 Bits
Data Register (Accumulator)
DF
1-Bit
Data Flag (ALU Carry)
B
8 Bits
Auxiliary Holding Register
R
16 Bits
1 of 16 Scratch and Registers
P
4 Bits
Designates which Register is Program
Counter
3. Input instructions.
X
4 Bits
Designates which Register is Data Pointer
4. Register to memory transfer.
N
4 Bits
Holds Low-Order Instr. Digit
5. Memory to register transfer.
I
4 Bits
Holds High-Order Instr. Digit
6. Interrupt and subroutine handling.
T
8 Bits
Holds old X, P after Interrupt (X is high nibble)
The register designated by N (i.e., R(N)) points to memory
for the “load D from memory” instructions ON and 4N and
the “Store D” instruction 5N. The register designated by P
(i.e., the program counter) is used as the data pointer for
ALU instructions F8-FD, FF, 7C, 7D, 7F, and the RLDl
instruction 68CN. During these instruction executions, the
operation is referred to as “data immediate”.
11
Q
1-Bit
CNTR
8-Bits
Counter/Timer
Output Flip-Flop
CH
8 Bits
Holds Counter Jam Value
MIE
1-Bit
Master Interrupt Enable
ClE
1-Bit
Counter Interrupt Enable
XlE
1-Bit
External Interrupt Enable
ClL
1-Bit
Counter Interrupt Latch
CDP1805AC, CDP1806AC
Interrupt Servicing
latched counter interrupt request signal will be reset when
the branch is taken, when the CPU is reset, or with a LDC
instruction with the Counter stopped. Note, that exiting a
counter-initiated interrupt routine without resetting the
counter-interrupt latch will result in immediately reentering
the interrupt routine.
Register R(1) is always used as the program counter whenever interrupt servicing is initialized. When an interrupt
request occurs and the interrupt is allowed by the program
(again, nothing takes place until the completion of the current instruction), the contents of the X and P registers are
stored in the temporary Register T, and X and P are set to
new values; hex digit 2 in X and hex digit 1 in P. Master Interrupt Enable is automatically deactivated to inhibit further
interrupts. The user’s interrupt routine is now in control; the
contents of T may be saved by means of a single SAV
instruction (78) in the memory location pointed to by R(X) or
the contents of T, D, and DF may be saved using a single
DSAV instruction (6876). At the conclusion of the interrupt,
the user's routine may restore the pre-interrupted value of X
and P with either a RET instruction (70) which permits further interrupts, or a DlS instruction (71), which disables further interrupts.
Counter/Timer and Controls (See Figure 7)
This logic consists of a presettable 8-Bit down-counter (Modulo N type), and a conditional divide-by-32 prescaler. After
counting down to (01)16the counter returns to its initial value
at the next count and sets the Counter Interrupt Latch. It will
continue decrementing on subsequent counts. If the counter
is preset to (00)16 full 256 counts will occur.
During a Load Counter instruction (LDC) if the counter was
stopped with a STPC Instruction, the counter and its holding
register (CH) are loaded with the value in the D Register and
any previous counter interrupt is cleared. If the LDC is executed when the counter is running, the contents of the D
Register are loaded into the holding register (CH) only and
any previous counter interrupt is not cleared. (LDC RESETS
the Counter Interrupt Latch only when the Counter is
stopped). After counting down to (01)16 the next count will
load the new initial value into the counter, set the Counter
Interrupt Latch, and operation will continue.
Interrupt Generation and Arbitration (See Figure 6)
Interrupt requests can be generated from the following
sources:
1. Externally through the interrupt input (request not
latched).
2. Internally due to Counter/Timer response (request is
latched).
a. On the transition from count (01)16 to its next value
(counter underflow).
b. On the
mode 1.
transition of EF1 in pulse measurement
c. On the
mode 2.
transition of EF2 in pulse measurement
For an interrupt to be serviced by the CPU, the appropriate
Interrupt Enable flip-flops must be set. Thus, the External
Interrupt Enable flip-flop must be set to service an external
interrupt request, and the Counter Interrupt Enable flip-flop
must be set to service an internal Counter/Timer interrupt
request. In addition, the Master interrupt Enable flip-flop (as
used in the CDP1802) must be set to service either type of
request. All 3 flip-flops are initially enabled with the application of a hardware reset, and, can be selectively enabled or
disabled with software: ClE, ClD instructions for the ClE flipflop; XlE, XlD instructions for the XIE flip-flop; RET, DIS
instructions for the MIE flip flop.
Short branch instructions on Counter Interrupt (BCI) and
External Interrupt (BXl) can be placed in the user's interrupt
service routine to provide a means of identifying and prioritizing the interrupt source. Note, however, that since the
External Interrupt request is not latched, it must remain
active until the short branch is executed if this priority arbitration scheme is used.
Interrupt requests can also be polled if automatic interrupt
service is not desired (MlE = 0). With the Counter Interrupt
and External Interrupt short branch instructions, the branch
will be taken if an interrupt request is pending, regardless of
the state of any of the 3 Interrupt Enable flip-flops. The
12
CDP1805AC, CDP1806AC
RET
RESET
S3
MASTER
Q
INTERRUPT
ENABLE
FF
R
(MIE)
S
DIS
MIE
COUNTER
UNDERFLOW
S
PULSE MODE EF1
PULSE MODE EF2
BCI
CIE
RESET
CID
S COUNTER
INTERRUPT
ENABLE
FF
R
Q
(CIE)
R
RESET
LDC • COUNTER
STOPPED
RESET
XID
CI
INTERRUPT
XI
EXTERNAL INT
XIE
TO BRANCH
LOGIC (BCI)
Q
COUNTER
INTERRUPT
LATCH
(CIL)
TO BRANCH
LOGIC (BXI)
REQUESTS
EXTERNAL
Q
INTERRUPT
ENABLE
FF
R
(XIE)
S
FIGURE 6. INTERRUPT LOGIC CONTROL DIAGRAM
The Counter/Timer has the following five programmable
modes:
The modes can be changed without affecting the stored
count.
1. Event Counter 1: Input to counter is connected to the EF1
terminal. The high-to-low transition decrements the
counter.
Those modes which use EF1 and EF2 terminals as inputs do
not exclude testing these flags for branch instructions.
2. Event Counter 2: Input to counter is connected to the EF2
terminal. The high-to-low transition decrements the
counter.
The Stop Counter (STPC) instruction clears the counter
mode and stops counting. The STPC instruction should be
executed prior to a GEC instruction, if the counter is in the
Event Counter Mode 1 or 2.
3. Timer: Input to counter is from the divide by 32 prescaler
clocked by TPA. The prescaler is decremented on the
low-to-high transition of TPA. The divide by 32 prescaler
is reset when the counter is in a mode other than the
Timer mode, system RESET, or stopped by a STPC.
In addition to the five programmable modes, the Decrement
Counter instruction (DTC) enables the user to count in software. In order to avoid conflict with counting done in the
other modes, the instruction should be used only after the
mode has been cleared by a Stop Counter instruction.
4. Pulse Duration Measurement 1: Input to counter connected to TPA. Each low-to-high transition of TPA decrements the counter if the input signal at EF1 terminal (gate
input) is low. On the transition of EF1 to the positive state,
the count is stopped, the mode is cleared, and the interrupt request latched. If the counter underflows while the
input is low, interrupt will also be set, but counting will
continue.
The Enable Toggle Q instruction (ETQ) connects the Q-line
flip-flop to the output of the counter, such that each time the
counter decrements from 01 to its next value, the Q output
changes state. This action is independent of the counter
mode and the Interrupt Enable flip-flops. The Enable Toggle
Q condition is cleared by an LDC with the Counter/Timer
stopped, system Reset, or a BCl with Cl = 1.
NOTE: SEQ and REQ instructions are independent of ETQ, they
can SET or RESET Q while the Counter is running.
5. Pulse Duration Measurement 2: Operation is identical to
Pulse Duration Measurement 1, except EF2 is used as
the gate input.
On-Board Clock (See Figure 8, Figure 9 and Figure 10)
Clock circuits may use either an external crystal or an RC
network.
A typical crystal oscillator circuit is shown in Figure 8. The
crystal is connected between terminals 1 and 39 (CLOCK
and XTAL) in parallel with a resistance, RF (1mΩ typ). Frequency trimming capacitors, CIN and COUT, may be required
at terminals 1 and 39. For additional information on crystal
oscillators, see lCAN-6565.
13
CDP1805AC, CDP1806AC
STPC
STM
R
÷ 32
TPA
TO INTERRUPT LATCH
INH
OUT
SPMI
COUNTER
UNDERFLOW
Q
ETQ
8-BIT
DOWN
COUNTER
EF1
Q OUTPUT
C
Q FF
D
Q
LDC
LOAD
SCMI
READ
EF2
SPM2
SCM2
DTC
GEC
FIGURE 7. TIMER/COUNTER DIAGRAM
Because of the Schmitt Trigger input, an RC oscillator can
be used as shown in Figure 9. The frequency is approximately 1/RC (see Figure 10).
VDD = 5V AT 25oC
10M
C
RF
R (Ω)
C
1MΩ
1M
C
C
CLOCK† 1
=
100K
39 XTAL †
1µ
C
=
0.
1µ
F
=
0 .0
1µ
=
F
=
10
00
pF
10
0p
F
pF
10K
XTAL
CIN
15pF
5MHz PARALLEL
RESONANT
CRYSTAL
COUT
27pF
1
10
100
1K
10K
100K
1M
FREQUENCY (Hz)
FIGURE 10. NOMINAL COMPONENT VALUES AS A FUNCTION
OF FREQUENCY FOR THE RC OSCILLATOR
†Pin numbers refer to 40 pin DIP.
FIGURE 8. TYPICAL 5MHz CRYSTAL OSCILLATOR
CONTROL MODES
R
CLOCK† 1
39 XTAL †
C
†Pin numbers refer to 40 pin DIP.
FIGURE 9. RC NETWORK FOR OSCILLATOR
14
CLEAR
WAIT
MODE
L
L
Not Allowed
L
H
Reset
H
L
Pause
H
H
Run
CDP1805AC, CDP1806AC
The function of the modes are defined as follows:
Power-up Reset/Run Circuit
Reset
Power-up Reset/Run can be realized with the circuit shown
in Figure 11.
VDD
The levels on the CDP1805A and CDP1806A external signal
lines will asynchronously be forced by RESET to the following states:
Q=0
MRD = 1
TPB = 0
CDP1805AC
CDP1806AC
SC1, SC0 = 0,1
BUS 0-7 = 0
(EXECUTE)
MA0-7 = RO.1
N0, N1, N2 = 0, 0, 0 TPA = 0
MWR = 1
RP
WAIT
RX
CLEAR
THE RC TIME CONSTANT
SHOULD BE GREATER THAN
THE OSCILLATOR START-UP
TIME (TYPICALLY 20ms)
Internal Changes Caused By RESET are:
CX
l, N Instruction Register is cleared to 00. XlE and CIE are set
to allow interrupts following initialize. ClL is cleared (any
pending counter interrupt is cleared), counter is stopped, the
counter mode is cleared, and ETQ is disabled.
FIGURE 11. RESET/RUN DIAGRAM
Initialization Cycle
Pause
The first machine cycle following termination of RESET is an
initialization cycle which requires 9 clock pulses. During this
cycle the CPU remains in S1 and the following additional
changes occur:
Pause is a low power mode which stops the internal CPU
timing generator and freezes the state of the processor. The
CPU may be held in the Pause mode indefinitely. Hardware
pause can occur at two points in a machine cycle, on the
low-to-high transition of either TPA or TPB. A TPB pause can
also be initiated by software with the execution of an IDLE
instruction. In the pause mode, the oscillator continues to run
but subsequent clock transitions are ignored. TPA and TPB
remain at their previous state (see Figure 12).
1 → MlE
X, P → T (The old value of X, P will be put into T. This
only has meaning following an orderly Reset with power
applied).
X, P, RO ← 0 (X, P, and RO are cleared).
Pause is entered from RUN by dropping WAIT low. Appropriate Setup and Hold times must be met.
Interrupt and DMA servicing is suppressed during the initialization cycle. The next cycle is an S0 or an S2 but never an
S1 or S3.The use of a 71 instruction followed by 00 at memory locations 0000 and 0001, may be used to reset MIE so
as to preclude interrupts until ready for them.
If Pause is entered while in the event counter mode, the
appropriate Flag transition will continue to decrement the
counter.
Hardware-initiated pause is exited to RUN by raising the
Wait line high. Pause entered with an IDLE instruction
requires DMA, INTERRUPT or RESET to resume execution.
Reset and Initialize Do Not Affect:
D (Accumulator)
DF
R1, R2, R3, R4, R5, R6, R7, R8, R9, FA, RB, RC, RD, RE, RF
CH (Counter Holding Register)
Counter (the counter is stopped but the value is unaffected)
Run
May be initiated from the Pause or Reset mode functions. If
initiated from Pause, the CPU resumes operation at the
point it left off. If paused at TPA, it will resume on the next
high-to-low clock transition, while if paused at TPB, it will
resume on the next low-to-high clock transition (see Figure
12). When initiated from the Reset operation, the first
machine cycle following Reset is always the initialization
cycle. The initialization cycle is then followed by a DMA (S2)
cycle or fetch (S0) from location 0000 in memory.
Schmitt Trigger Inputs
All inputs except BUS 0-BUS 7 and ME contain a Schmitt
Trigger circuit, which is especially useful on the CLEAR input
as a power-up RESET (see Figure 11) and the CLOCK input
(see Figure 8 and Figure 9).
15
CDP1805AC, CDP1806AC
State Transitions
The CDP1805A and CDP1806A state transitions are shown
in Figure 13. Each machine cycle requires the same period
of time, 8 clock pulses, except the initialization cycle (INlT)
which requires 9 clock pulses. Reset is asynchronous and
can be forced at any time.
ENTER RESUME
PAUSE
RUN
ENTER RESUME
PAUSE
RUN
PAUSE
PAUSE
CLOCK
70
71
00
01
10
11
20
21
50
CLOCK
30
51
60
61
70
71
00
01
10
PAUSE
PAUSE
tPLH
tPLH
TPB
tPHL
tPHL
TPA
WAIT
WAIT
tSU
tSU
tH
tSU
tH
tSU
NOTE:
9. Pause (in clock waveform) while represented here as one clock
cycle in duration, could be infinitely long.
FIGURE 12A. TPA PAUSE TIMING
FIGURE 12B. TPB PAUSE TIMING
FIGURE 12. PAUSE MODE TIMING WAVEFORMS
RESET
INT • DMA • RESET
PAUSE
IDLE • DMA • INT
S1 RESET
FORCE S1
DMA + INT
(LONG BRANCH,
LONG SKIP, NOP, RSXD, ETC)
DMA • FORCE S1
S1 EXECUTE
S1 INIT
DMA
DMA
DMA • IDLE • INT
• FORCE S1
DMA
INT • DMA • FORCE S1
FORCE S0
PRIORITY:
S2 DMA
DMA
SO FETCH
DMA • INT
S3 INT
“68”
FORCE S0
DMA
INT • DMA
FIGURE 13. STATE TRANSITION DIAGRAM
16
RESET
FORCE S0, S1
DMA IN
DMA OUT
INT
CDP1805AC, CDP1806AC
Instruction Set
R(W).0: Lower-order byte of R(W)
The CDP1805AC and CDP1806AC instruction summary is
given in Table 1. Hexadecimal notation is used to refer to the
4-bit binary codes.
R(W).1: Higher-order byte of R(W)
Operation Notation
In all registers, bits are numbered from the least significant
bit (LSB) to the most significant bit (MSB) starting with 0.
M (R(N)) → D; R(N) + 1 → R(N)
R(W): Register designated by W, where
This notation means: The memory byte pointed to by R(N) is
loaded into D, and R(N) is incremented by 1.
W = N or X, or P
TABLE 1. INSTRUCTION SUMMARY (SEE NOTES)
NO. OF
MACHINE
CYCLES
MNEMONIC
OP CODE
LOAD IMMEDIATE
2
LDI
F8
REGISTER LOAD IMMEDIATE
5
RLDI
68CN
(Note 10)
LOAD VIA N
2
LDN
0N
M(R(N)) → D; FOR N NOT 0
LOAD ADVANCE
2
LDA
4N
M(R(N)) → D; R(N) + 1 → R(N)
LOAD VIA X
2
LDX
F0
M(R(X)) → D
LOAD VIA X AND ADVANCE
2
LDXA
72
M(R(X)) → D; R(X) + 1 → R(X)
REGISTER LOAD VIA X AND
ADVANCE
5
RLXA
686N
(Note 10)
STORE VIA N
2
STR
5N
D → M(RN))
STORE VIA X AND DECREMENT
2
STXD
73
D → M(R(X)); R(X) - 1 → R(X)
REGISTER STORE VIA X AND
DECREMENT
5
RSXD
68AN
(Note 10)
R(N).0 → M(R(X)); R(N).1 →
M(R)(X) - 1); R(X) - 2 → R (X)
INCREMENT REG N
2
INC
1N
R(N) + 1 → R(N)
DECREMENT REG N
2
DEC
2N
R(N) - 1 → R(N)
DECREMENT REG N AND LONG
BRANCH IF NOT EQUAL 0
5
DBNZ
682N
INCREMENT REG X
2
IRX
60
R(X) + 1 → R(X)
GET LOW REG N
2
GLO
8N
R(N).0 → D
PUT LOW REG N
2
PLO
AN
D → R(N).0
GET HIGH REG N
2
GHI
9N
R(N).1 → D
PUT HIGH REG N
2
PHI
BN
D → R(N).1
REGISTER N TO REGISTER X
COPY
4
RNX
68BN
(Note 10)
R(N) → R(X)
OR
2
OR
F1
M(R(X)) OR D → D
OR IMMEDIATE
2
ORI
F9
M(R(P)) OR D → D; R(P) + 1 → R(P)
EXCLUSIVE OR
2
XOR
F3
M(R(X)) XOR D → D
EXCLUSIVE OR IMMEDIATE
2
XRI
FB
M(R(P)) XOR D → D;
R(P) + 1 → R(P)
AND
2
AND
F2
M(R(X)) AND D → D
INSTRUCTION
OPERATION
MEMORY REFERENCE
M(R(P)) → D; R(P) + 1 → R(P)
M(R(P)) → R(N).1; M(R(P)) + 1 →
R(N).0; R(P) + 2 → R(P)
M(R(X)) → R(N).1; M(R(X) + 1) →
R(N).0; R(X)) + 2 → R(X)
REGISTER OPERATIONS
R(N) - 1 → R(N); IF R(N) NOT 0,
M(R(P)) → R(P).1, M(R(P) + 1) →
R(P).0, ELSE R(P) + 2 → R(P)
LOGIC OPERATIONS (Note 19)
17
CDP1805AC, CDP1806AC
TABLE 1. INSTRUCTION SUMMARY (SEE NOTES) (Continued)
NO. OF
MACHINE
CYCLES
MNEMONIC
OP CODE
AND IMMEDIATE
2
ANI
FA
M(R(P)) AND D → D; R(P) + 1 → R(P)
SHIFT RIGHT
2
SHR
F6
Shift D Right, LSB(D) → DF, 0 → MSB(D)
SHIFT RIGHT WITH CARRY
2
SHRC
76
(Note 11)
Shift D Right, LSB(D) → DF, DF → MSB(D)
RING SHIFT RIGHT
2
RSHR
76
(Note 11)
SHIFT D RIGHT, LSB(D) → DF, DF → MSB(D)
SHIFT LEFT
2
SHL
FE
SHIFT LEFT WITH CARRY
2
SHLC
7E
(Note 11)
SHIFT D LEFT, MSB(D) → DF, DF → LSB(D)
RING SHIFT LEFT
2
RSHL
7E
(Note 11)
SHIFT D LEFT, MSB(D) → DF, DF → LSB(D)
ADD
2
ADD
F4
DECIMAL ADD
4
DADD
68F4
ADD IMMEDIATE
2
ADI
FC
M(R(P)) + D → DF, D; R(P) + 1 → R(P)
DECIMAL ADD IMMEDIATE
4
DADI
68FC
M(R(P)) + D → DF, D; R(P) + 1 → R(P)
DECIMAL ADJUST → DF, D
ADD WITH CARRY
2
ADC
74
DECIMAL ADD WITH CARRY
4
DADC
6874
M(R(X)) + D + DF → DF, D
DECIMAL ADJUST → DF, D
ADD WITH CARRY, IMMEDIATE
2
ADCI
7C
M(R(P)) + D + DF → DF, D;
R(P) + 1 → R(P)
DECIMAL ADD WITH CARRY,
IMMEDIATE
4
DACI
687C
M(R(P)) + D + DF → DF, D;
R(P) + 1 → R(P),
DECIMAL ADJUST → DF, D
SUBTRACT D
2
SD
F5
M(R(X)) - D → DF, D
SUBTRACT D IMMEDIATE
2
SDI
FD
M(R(P)) - D → DF, D;
R(P) + 1 → R(P)
SUBTRACT D WITH BORROW
2
SDB
75
M(R(X)) - D - (NOT DF) → DF, D
SUBTRACT D WITH BORROW,
IMMEDIATE
2
SDBI
7D
M(R(P)) - D - (NOT DF) → DF, D;
R(P) + 1 → R(P)
SUBTRACT MEMORY
2
SM
F7
D - M(R(X)) → DF, D
DECIMAL SUBTRACT MEMORY
4
DSM
68F7
SUBTRACT MEMORY IMMEDIATE
2
SMI
FF
DECIMAL SUBTRACT MEMORY,
IMMEDIATE
4
DSMI
68FF
SUBTRACT MEMORY WITH
BORROW
2
SMB
77
D - M(R(X)) - (NOT DF) → DF, D
DECIMAL SUBTRACT MEMORY
WITH BORROW
4
DSMB
6877
D - M(R(X)) - (NOT DF) → DF, D;
DECIMAL ADJUST → DF, D
SUBTRACT MEMORY WITH
BORROW, IMMEDIATE
2
SMBI
7F
D - M(R(P)) - (NOT DF) → DF, D;
R(P) + 1 → R(P)
INSTRUCTION
OPERATION
SHIFT D LEFT, MSB(D) → DF, 0 → LSB(D)
ARITHMETIC OPERATIONS (Note 3)
18
M(R(X)) + D → DF, D
M(R(X)) + D → DF, D DECIMAL ADJUST → DF, D
M(R(X)) + D + DF → DF, D
D - M(R(X)) → DF, D; DECIMAL ADJUST → DF, D
D - M(R(P)) → DF, D; R(P) + 1 → R(P)
D - M(R(P)) → DF, D;
R(P) + 1 → R(P),
DECIMAL ADJUST → DF, D
CDP1805AC, CDP1806AC
TABLE 1. INSTRUCTION SUMMARY (SEE NOTES) (Continued)
INSTRUCTION
DECIMAL SUBTRACT MEMORY
WITH BORROW, IMMEDIATE
NO. OF
MACHINE
CYCLES
MNEMONIC
OP CODE
4
DSBI
687F
OPERATION
D - M(R(P)) - (NOT DF) → DF, D
R(P) + 1 → R(P)
DECIMAL ADJUST → DF, D
BRANCH INSTRUCTIONS - SHORT BRANCH
M(R(P)) → R(P).0
SHORT BRANCH
2
BR
30
NO SHORT BRANCH (See SKP)
2
NBR
38
(Note 11)
SHORT BRANCH IF D = 0
2
BZ
32
IF D = 0, M(R(P)) → R(P).0
ELSE R(P) + 1 → R(P)
SHORT BRANCH IF D NOT 0
2
BNZ
3A
IF D NOT 0, M(R(P)) → R(P).0
ELSE R(P) + 1 → R(P)
SHORT BRANCH IF DF = 1
2
BDF
33
(Note 11)
IF DF = 1, M(R(P)) → R(P).0
ELSE R(P) + 1 → R(P)
SHORT BRANCH IF POS OR ZERO
2
BPZ
33
(Note 11)
IF DF = 1, M(R(P)) → R(P).0
ELSE R(P) + 1 → R(P)
SHORT BRANCH IF EQUAL OR
GREATER
2
BGE
33
(Note 11)
IF DF = 1, M(R(P)) → R(P).0,
ELSE R(P) + 1 → R(P)
SHORT BRANCH IF DF = 0
2
BNF
3B
(Note 11)
IF D = 0, M(R(P)) → R(P).0,
ELSE R(P) + 1 → R(P)
SHORT BRANCH IF MINUS
2
BM
3B
(Note 11)
IF D = 0, M(R(P)) → R(P).0,
ELSE R(P) + 1 → R(P)
SHORT BRANCH IF LESS
2
BL
3B
(Note 11)
IF D = 0, M(R(P)) → R(P).0,
ELSE R(P) + 1 → R(P)
SHORT BRANCH IF Q = 1
2
BQ
31
IF Q = 1, M(R(P)) → R(P).0
ELSE R(P) + 1 → R(P)
SHORT BRANCH IF Q = 0
2
BNQ
39
IF Q = 0, M(R(P)) → R(P).0
ELSE R(P) + 1 → R(P)
SHORT BRANCH IF EF1 = 1
(EF1 = VSS)
2
B1
34
IF EF1 = 1, M(R(P)) → R(P).0
ELSE R(P) + 1 → R(P)
SHORT BRANCH IF EF1 = 0
(EF1 = VDD)
2
BN1
3C
IF EF1 = 0, M(R(P)) → R(P).0
ELSE R(P) + 1 → R(P)
SHORT BRANCH IF EF2 = 1
(EF2 = VSS)
2
B2
35
IF EF2 = 1, M(R(P)) → R(P).0
ELSE R(P) + 1 → R(P)
SHORT BRANCH IF EF2 = 0
(EF2 = VDD)
2
BN2
3D
IF EF2 = 0, M(R(P)) → R(P).0
ELSE R(P) + 1 → R(P)
SHORT BRANCH IF EF3 = 1
(EF3 = VSS)
2
B3
36
IF EF3 = 1, M(R(P)) → R(P).0
ELSE R(P) + 1 → R(P)
SHORT BRANCH IF EF3 = 0
(EF3 = VDD)
2
BN3
3E
IF EF3 = 0, M(R(P)) → R(P).0
ELSE R(P) + 1 → R(P)
SHORT BRANCH IF EF4 = 1
(EF4 = VSS)
2
B4
37
IF EF4 = 1, M(R(P)) → R(P).0
ELSE R(P) + 1 → R(P)
SHORT BRANCH IF EF4 = 0
(EF4 = VDD)
2
BN4
3F
IF EF4 = 0, M(R(P)) → R(P).0
ELSE R(P) + 1 → R(P)
SHORT BRANCH ON COUNTER
INTERRUPT
3
BCI
683E
(Note 12)
SHORT BRANCH ON EXTERNAL
INTERRUPT
3
BXI
683F
19
R(P) + 1 → R(P)
IF CI = 1, M(R(P)) → R(P).0; 0 → CI
ELSE R(P) + 1 → R(P)
IF XI = 1, M(R(P)) → R(P).0
ELSE R(P) + 1 → R(P)
CDP1805AC, CDP1806AC
TABLE 1. INSTRUCTION SUMMARY (SEE NOTES) (Continued)
INSTRUCTION
NO. OF
MACHINE
CYCLES
MNEMONIC
OP CODE
OPERATION
BRANCH INSTRUCTIONS - LONG BRANCH
M(R(P)) → R(P).1, M(R(P) + 1) → R(P).0
LONG BRANCH
3
LBR
C0
NO LONG BRANCH (See LSKP)
3
NLBR
C8
(Note 11)
LONG BRANCH IF D = 0
3
LBZ
C2
IF D = 0, M(R(P)) → R(P).1
M(R(P) + 1) → R(P).0
ELSE R(P) + 2 → R(P)
LONG BRANCH IF D NOT 0
3
LBNZ
CA
IF D NOT 0, M(R(P)) → R(P).1
M(R(P) + 1) → R(P).0
ELSE R(P) + 2 → R(P)
LONG BRANCH IF DF = 1
3
LBDF
C3
IF DF = 1, M(R(P)) → R(P).1
M(R(P) + 1) → R(P).0
ELSE R(P) + 2 → R(P)
LONG BRANCH IF DF = 0
3
LBNF
CB
IF DF = 0, M(R(P)) → R(P).1
M(R(P) + 1) → R(P).0
ELSE R(P) + 2 → R(P)
LONG BRANCH IF Q = 1
3
LBQ
C1
IF Q = 1, M(R(P)) → R(P).1
M(R(P) + 1) → R(P).0
ELSE R(P) + 2 → R(P)
LONG BRANCH IF Q = 0
3
LBNQ
C9
IF Q = 0, M(R(P)) → R(P).1
M(R(P) + 1) → R(P).0
ELSE R(P) + 2 → R(P)
SHORT SKIP (See NBR)
2
SKP
38
(Note 11)
R(P) + 1 → R(P)
LONG SKIP (See NLBR)
3
LSKP
C8
(Note 11)
R(P) + 2 → R(P)
LONG SKIP IF D = 0
3
LSZ
CE
IF D = 0, R(P) + 2 → R(P)
ELSE CONTINUE
LONG SKIP IF D NOT 0
3
LSNZ
C6
IF D NOT 0, R(P) + 2 → R(P)
ELSE CONTINUE
LONG SKIP IF DF = 1
3
LSDF
CF
IF DF = 1, R(P) + 2 → R(P)
ELSE CONTINUE
LONG SKIP IF DF = 0
3
LSNF
C7
IF DF = 0, R(P) + 2 → R(P)
ELSE CONTINUE
LONG SKIP IF Q = 1
3
LSQ
CD
IF Q = 1, R(P) + 2 → R(P)
ELSE CONTINUE
LONG SKIP IF Q = 0
3
LSNQ
C5
IF Q = 0, R(P) + 2 → R(P)
ELSE CONTINUE
LONG SKIP IF MIE = 1
3
LSIE
CC
IF MIE = 1, R(P) + 2 → R(P)
ELSE CONTINUE
IDLE
2
IDL
00
(Note 14)
NO OPERATION
3
NOP
C4
CONTINUE
SET P
2
SEP
DN
N→P
SET X
2
SEX
EN
N→X
R(P) + 2 → R(P)
SKIP INSTRUCTIONS
CONTROL INSTRUCTIONS
20
STOP ON TPB; WAIT FOR DMA OR INTERRUPT;
BUS FLOATS
CDP1805AC, CDP1806AC
TABLE 1. INSTRUCTION SUMMARY (SEE NOTES) (Continued)
NO. OF
MACHINE
CYCLES
MNEMONIC
OP CODE
SET Q
2
SEQ
7B
1→Q
RESET Q
2
REQ
7A
0→Q
PUSH X, P TO STACK
2
MARK
79
(X, P) → T; (X, P) → M(R(2)),
THEN P → X; R(2) → 1→ R(2)
LOAD COUNTER
3
LDC
6806
(Note 15)
GET COUNTER
3
GEC
6808
CNTR → D
STOP COUNTER
3
STPC
6800
STOP CNTR CLOCK;
0 → ÷ 32 PRESCALER
DECREMENT TIMER/COUNTER
3
DTC
6801
CNTR - 1 → CNTR
SET TIMER MODE AND START
3
STM
6807
TPA ÷ 32 → CNTR
SET COUNTER MODE 1 AND
START
3
SCM1
6805
EF1 → CNTR CLOCK
SET COUNTER MODE 2 AND
START
3
SCM2
6803
EF2 → CNTR CLOCK
SET PULSE WIDTH MODE 1 AND
START
3
SPM1
6804
TPA.EF1 → CNTR CLOCK;
STOPS COUNT
EF1
SET PULSE WIDTH MODE 2 AND
START
3
SPM2
6802
TPA.EF2 → CNTR CLOCK;
STOPS COUNT
EF2
ENABLE TOGGLE Q
3
ETQ
6809
(Note 15)
EXTERNAL INTERRUPT ENABLE
3
XIE
680A
1 → XIE
EXTERNAL INTERRUPT DISABLE
3
XID
680B
0 → XIE
COUNTER INTERRUPT ENABLE
3
CIE
680C
l → CIE
COUNTER INTERRUPT DISABLE
3
CID
680D
0 → CIE
RETURN
2
RET
70
M(R(X)) → X, P; R(X) + 1 → R(X); 1 → MIE
DISABLE
2
DIS
71
M(R(X) → X, P; R(X) + 1 → R(X); 0 → MIE
SAVE
2
SAV
78
T → M(R(X))
SAVE T, D, DF
6
DSAV
6876
(Note 10)
OUTPUT 1
2
OUT 1
61
M(R(X)) → BUS; R(X) + 1 → R(X)
N LINES = 1
OUTPUT 2
2
OUT 2
62
M(R(X)) → BUS; R(X) + 1 → R(X)
N LINES = 2
OUTPUT 3
2
OUT 3
63
M(R(X)) → BUS; R(X) + 1 → R(X)
N LINES = 3
OUTPUT 4
2
OUT 4
64
M(R(X)) → BUS; R(X) + 1 → R(X)
N LINES = 4
OUTPUT 5
2
OUT 5
65
M(R(X)) → BUS; R(X) + 1 → R(X)
N LINES = 5
INSTRUCTION
OPERATION
TIMER/COUNTER INSTRUCTIONS
CNTR STOPPED: D → CH, CNTR;
0 → CI. CNTR RUNNING; D → CH
IF CNTR = 01 • NEXT CNTR CLOCK
INTERRUPT CONTROL
R(X) - 1 → R(X), T → M(R(X)),
R(X) - 1 → R(X), D → M (R(X)),
R(X) - 1 → R(X), SHIFT D
RIGHT WITH CARRY, D → M(R(X))
INPUT-OUTPUT BYTE TRANSFER
21
;Q→Q
CDP1805AC, CDP1806AC
TABLE 1. INSTRUCTION SUMMARY (SEE NOTES) (Continued)
NO. OF
MACHINE
CYCLES
MNEMONIC
OP CODE
OUTPUT 6
2
OUT 6
66
M(R(X)) → BUS; R(X) + 1 → R(X)
N LINES = 6
OUTPUT 7
2
OUT 7
67
M(R(X)) → BUS; R(X) + 1 → R(X)
N LINES = 7
INPUT 1
2
INP 1
69
BUS → M(R(X)); BUS → D
N LINES = 1
INPUT 2
2
INP 2
6A
BUS → M(R(X)); BUS → D
N LINES = 2
INPUT 3
2
INP 3
6B
BUS → M(R(X)); BUS → D
N LINES = 3
INPUT 4
2
INP 4
6C
BUS → M(R(X)); BUS → D
N LINES = 4
INPUT 5
2
INP 5
6D
BUS → M(R(X)); BUS → D
N LINES = 5
INPUT 6
2
INP 6
6E
BUS → M(R(X)); BUS → D
N LINES = 6
INPUT 7
2
INP 7
6F
BUS → M(R(X)); BUS → D
N LINES = 7
STANDARD CALL
10
SCAL
688N
(Note 10)
R(N).0 → M(R(X));
R(N).1 → M(R(X) - 1);
R(X) - 2 → R(X); R(P) → R(N);
THEN M(R(N)) → R(P).1;
M(R(N) + 1) → R(P).0;
R(N) + 2 → R(N)
STANDARD RETURN
8
SRET
689N
(Note 10)
R(N) → R(P);
M(R(X) + 1) → R(N).1;
M(R(X) + 2) → R(N).0; R(X) + 2 → R(X)
INSTRUCTION
OPERATION
CALL AND RETURN
NOTES:
10. Previous contents of T register are destroyed during instruction execution.
11. This instruction is associated with more than one mnemonic. Each mnemonic is individually listed.
12. ETQ cleared by LDC with the Counter/Timer stopped, reset of CPU, or BCl • (Cl = 1).
13. Cl = Counter Interrupt, Xl = External Interrupt.
14. An IDLE instruction initiates an S1 cycle. All external signals, except the oscillator, are stopped on the low-to-high transition of TPB. All
outputs remain in their previous states, MRD, MWR, are set to a logic ‘1’ and the data bus floats. The processor will continue to IDLE
until an I/O request (INTERRUPT, DMA-IN, or DMA-OUT) is activated. When the request is acknowledged, the IDLE cycle is terminated
and the I/O request is serviced, and the normal operation is resumed. (To respond to an lNTERRUPT during an IDLE, MlE and either
ClE or XlE must be enabled).
15. Long-Branch, Long-Skip and No Op instructions require three cycles to complete (1 fetch + 2 execute).
Long-Branch instructions are three bytes long. The first byte specifies the condition to be tested; and the second and third byte, the
branching address.
The long branch instruction can:
a.
b.
c.
d.
e.
Branch unconditionally
Test for D = 0 or D ≠ 0
Test for DF = 0 or DF = 1
Test for Q = 0 or Q = 1
Effect an unconditional no branch
If the tested condition is met, then branching takes place; the branching address bytes are loaded in the high-and-low-order bytes of the
current program counter, respectively. This operation effects a branch to any memory location.
If the tested condition is not met, the branching address bytes are skipped over, and the next instruction in sequence is fetched and executed. This operation is taken for the case of unconditional no branch (NLBR).
22
CDP1805AC, CDP1806AC
16. The short-branch instructions are two or three bytes long. The first byte specifies the condition to be tested, and the second specifies the
branching address, except for the branches on interrupt. For those, the first two bytes specify the condition to be tested and the third byte
specifies the branching address.
The short branch instruction can:
a.
b.
c.
d.
e.
f.
g.
Branch unconditionally
Test for D = 0 or D ≠ 0
Test for DF = 0 or DF = 1
Test for Q = 0 or Q = 1
Test the status (1 or 0) of the four EF flags
Effect an unconditional no branch
Test for counter or external interrupts (BCI, BXI)
If the tested condition is met, then branching takes place; the branching address byte is loaded into the low-order byte position of the
current program counter. This effects a branch within the current 256-byte page of the memory, i.e., the page which holds the branching
address. If the tested condition is not met, the branching address byte is skipped over, and the next instruction in sequence is fetched
and executed. This same action is taken in the case of unconditional no branch (NBR).
17. The skip instructions are one byte long. There is one Unconditional Short-Skip (SKP) and eight Long-Skip instructions.
The Unconditional Short-Skip instruction takes 2 cycles to complete (1 fetch + 1 execute). Its action is to skip over the byte following it.
Then the next instruction in sequence is fetched and executed. This SKP instruction is identical to the unconditional No-Branch Instruction (NBR) except that the skipped-over byte is not considered part of the program.
The Long-Skip instructions take three cycles to complete (1 fetch + 2 execute).
They can:
a.
b.
c.
d.
e.
Skip unconditionally
Test for D = 0 or D ≠ 0
Test for DF = 0 or DF = 1
Test for Q = 0 or Q = 1
Test for MIE = 1
If the tested condition is met, then Long Skip takes place; the current program counter is incremented twice. Thus, two bytes are
skipped over and the next instruction in sequence is fetched and executed. If the tested condition is not met, then no action is taken.
Execution is continued by fetching the next instruction in sequence.
18. Instruction 6800 through 68FF take a minimum of 3 machine cycles and up to a maximum of 10 machine cycles. In all cases, the first two
cycles are fetches and subsequent cycles are executes. The first byte (68) of these two-byte op codes is used to generate the second
fetch, the second byte is then interpreted differently than the same code without the 68 prefix. DMA and INT requests are not serviced
until the end of the last execute cycle.
19. Arithmetic Operations:
The arithmetic and shift operations are the only instructions that can alter the content of DF. The syntax ‘(NOT DF)’ denotes the subtraction of the borrow.
Binary Operations:
After an ADD instruction
DF = 1 denotes a carry has occurred. Result is greater than FF16.
DF = 0 denotes a carry has not occurred.
After a SUBTRACT instruction
DF = 1 denotes no borrow. D is a true positive number.
DF = 0 denotes a borrow. D is in two's complement form.
Binary Coded Decimal Operations:
After a BCD ADD instruction
DF = 1 denotes a carry has occurred. Result is greater than 9910.
DF = 0 denotes a carry has not occurred.
After a BCD SUBTRACT instruction
DF = 1 denotes no borrow. D is a true positive decimal number.
Example
99
D
M(R(X))
-88
11
D
DF = 1
DF = 0 denotes a borrow. D is in ten's complement form.
Example
88
-99
89
D
M(R(X))
D
DF = 0
89 is the ten's complement of 11, which is the correct answer (with a minus value denoted by DF = 0).
23
CDP1805AC, CDP1806AC
TABLE 2. CONDITIONS ON DATA BUS AND MEMORY ADDRESS LINES DURING ALL MACHINE STATES
STATE
I
N
MNEMONIC
OPERATION
0 → Q, I, N, COUNTER,
PRESCALER, CIL;
1 → CIE, XIE
S1
RESET
S1
INITIALIZE, NOT PROGRAMMER ACCESSIBLE
S0
FETCH
X, P → T THEN
0 → X, P; 1 → MIE, 0000 → R0
MRP → I, N; RP + 1 → RP
MRD
MWR
N
LINES
UNDEFINED
1
1
0
00
(Note 20)
UNDEFINED
1
1
0
MRP
RP
0
1
0
HIGH Z
RO
1
1
0
MRN
RN
0
1
0
DATA
BUS
MEMORY
ADDRESS
00
S1
0
0
IDL
STOP AT TPB
WAIT FOR DMA OR INT
S1
0
1-F
LDN
MRN → D
S1
1
0-F
INC
RN + 1 → RN
HIGH Z
RN
1
1
0
S1
2
0-F
DEC
RN - 1 → RN
HIGH Z
RN
1
1
0
S1
3
0-F
SHORT
BRANCH
TAKEN: MRP → RP.0
NOT TAKEN: RP + 1 → RP
MRP
RP
0
1
0
S1
4
0-F
LDA
MRN → D; RN + 1 → RN
MRN
RN
0
1
0
S1
5
0-F
STR
D → MRN
D
RN
1
0
0
S1
6
0
IRX
RX + 1 → RX
MRX
RX
1
1
0
S1
6
1
OUT 1
MRX → BUS; RX + 1 → RX
MRX
RX
0
1
1
S1
6
2
OUT 2
MRX → BUS; RX + 1 → RX
MRX
RX
0
1
2
S1
6
3
OUT 3
MRX → BUS; RX + 1 → RX
MRX
RX
0
1
3
S1
6
4
OUT 4
MRX → BUS; RX + 1 → RX
MRX
RX
0
1
4
S1
6
5
OUT 5
MRX → BUS; RX + 1 → RX
MRX
RX
0
1
5
S1
6
6
OUT 6
MRX → BUS; RX + 1 → RX
MRX
RX
0
1
6
S1
6
7
OUT 7
MRX → BUS; RX + 1 → RX
MRX
RX
0
1
7
S1
6
9
INP 1
BUS → MRX, D
DATA
FROM
I/O
DEVICE
RX
1
0
1
S1
6
A
INP 2
BUS → MRX, D
DATA
FROM
I/O
DEVICE
RX
1
0
2
S1
6
B
INP 3
BUS → MRX, D
DATA
FROM
I/O
DEVICE
RX
1
0
3
S1
6
C
INP 4
BUS → MRX, D
DATA
FROM
I/O
DEVICE
RX
1
0
4
S1
6
D
INP 5
BUS → MRX, D
DATA
FROM
I/O
DEVICE
RX
1
0
5
24
CDP1805AC, CDP1806AC
TABLE 2. CONDITIONS ON DATA BUS AND MEMORY ADDRESS LINES DURING ALL MACHINE STATES (Continued)
DATA
BUS
MEMORY
ADDRESS
MRD
MWR
N
LINES
BUS → MRX, D
DATA
FROM
I/O
DEVICE
RX
1
0
6
INP 7
BUS → MRX, D
DATA
FROM
I/O
DEVICE
RX
1
0
7
0
RET
MRX → X, P; RX + 1 → RX
1 → MIE
MRX
RX
0
1
0
7
1
DIS
MRX → X, P; RX + 1 → RX
0 → MIE
MRX
RX
0
1
0
S1
7
2
LDXA
MRX → D; RX + 1 → RX
MRX
RX
0
1
0
S1
7
3
STXD
D → MRX; RX - 1 → RX
D
RX
1
0
0
S1
7
4
ADC
MRX + D + DF → DF, D
MRX
RX
0
1
0
S1
7
5
SDB
MRX - D - DFN → DF, D
MRX
RX
0
1
0
S1
7
6
SHRC
HIGH Z
RX
1
1
0
S1
7
7
SMB
D - MRX - DFN → DF, D
MRX
RX
0
1
0
S1
7
8
SAV
T → MRX
T
RX
1
0
0
S1
7
9
MARK
X, P → T, MR2; P → X
R2 - 1 → R2
T
R2
1
0
0
S1
7
A
REQ
0→Q
HIGH Z
RP
1
1
0
S1
7
B
SEQ
1→Q
HIGH Z
RP
1
1
0
S1
7
C
ADCI
MRP + D + DF → DF, D; RP + 1
MRP
RP
0
1
0
S1
7
D
SDBI
MRP - D - DFN → DF, D; RP + 1
MRP
RP
0
1
0
S1
7
E
SHLC
MSB(D) → DF; DF → LSB D
HIGH Z
RP
1
1
0
S1
7
F
SMBI
D - MRP - DFN → DF, D; RP + 1
MRP
RP
0
1
0
S1
8
0-F
GLO
RN.0 → D
RN.0
RN
1
1
0
S1
9
0-F
GHI
RN.1 → D
RN.1
RN
1
1
0
S1
A
0-F
PLO
D → RN.0
D
RN
1
1
0
S1
B
0-F
PHI
D → RN.1
D
RN
1
1
0
S1#1
C
0-3,
8-B
LONG
BRANCH
TAKEN: MRP → B; RP + 1 → RP
MRP
RP
0
1
0
#2
C
0-3,
8-B
LONG
BRANCH
TAKEN: B → RP.1; MRP →
RP.0
M(RP + 1)
RP + 1
0
1
0
S1#1
C
0-3,
8-B
LONG
BRANCH
NOT TAKEN RP + 1 → RP
MRP
RP
0
1
0
#2
C
0-3,
8-B
LONG
BRANCH
NOT TAKEN RP + 1 → RP
M(RP + 1)
RP + 1
0
1
0
S1#1
C
5
LONG
SKIP
TAKEN: RP + 1 → RP
MRP
RP
0
1
0
#2
C
6
LONG
SKIP
TAKEN: RP + 1 → RP
M(RP + 1)
RP + 1
0
1
0
STATE
I
N
MNEMONIC
S1
6
E
INP 6
S1
6
F
S1
7
S1
OPERATION
LSB(D) → DF; DF → MSB(D)
25
CDP1805AC, CDP1806AC
TABLE 2. CONDITIONS ON DATA BUS AND MEMORY ADDRESS LINES DURING ALL MACHINE STATES (Continued)
DATA
BUS
MEMORY
ADDRESS
MRD
MWR
N
LINES
M(RP + 1)
RP + 1
0
1
0
NOT TAKEN: NO OPERATION
MRP
RP
0
1
0
LONG
SKIP
NOT TAKEN: NO OPERATION
MRP
RP
0
1
0
E
LONG
SKIP
NOT TAKEN: NO OPERATION
M(RP + 1)
RP + 1
0
1
0
C
F
LONG
SKIP
NOT TAKEN: NO OPERATION
M(RP + 1)
RP + 1
0
1
0
S1#1
C
4
NOP
NO OPERATION
MRP
RP
0
1
0
#2
C
4
NOP
NO OPERATION
M(RP + 1)
RP + 1
0
1
0
S1
D
0-F
SEP
N→P
NN
RN
1
1
0
S1
E
0-F
SEX
N→X
NN
RN
1
1
0
S1
F
0
LDX
MRX → D
MRX
RX
0
1
0
S1
F
1
OR
MRX OR D → D
MRX
RX
0
1
0
S1
F
2
AND
MRX AND D → D
MRX
RX
0
1
0
S1
F
3
XOR
MRX XOR D → D
MRX
RX
0
1
0
S1
F
4
ADD
MRX + D → DF, D
MRX
RX
0
1
0
S1
F
5
SD
MRX - D → DF, D
MRX
RX
0
1
0
S1
F
7
SM
D - MRX → DF; D
MRX
RX
0
1
0
S1
F
6
SHR
LSB(D) → DF; 0 → MSB(D)
HIGH Z
RX
1
1
0
S1
F
8
LDI
MRP → D; RP + 1 → RP
MRP
RP
0
1
0
S1
F
9
ORI
MRP OR D → D; RP + 1 → RP
MRP
RP
0
1
0
S1
F
A
ANI
MRP AND D → D; RP + 1 → RP
MRP
RP
0
1
0
S1
F
B
XRI
MRP XOR D → D; RP + 1 → RP
MRP
RP
0
1
0
S1
F
C
ADI
MRP + D → DF, D; RP + 1 → RP
MRP
RP
0
1
0
S1
F
D
SDI
MRP - D → DF, D; RP + 1 → RP
MRP
RP
0
1
0
S1
F
F
SMI
D - MRP → DF, D; RP + 1 → RP
MRP
RP
0
1
0
S1
F
E
SHL
MSB(D) → DF; 0 → LSB(D)
HIGH Z
RP
1
1
0
S2
DMA IN
DMA IN
DMA IN
BUS → MR0; R0 + 1 → R0
DATA
FROM I/O
DEVICE
R0
1
0
0
S2
DMA OUT
DMA
OUT
DMA OUT
MRO → BUS; R0 + 1 → R0
MR0
R0
0
1
0
S3
INTERRUPT
INTERRUPT
INTERRUPT
HIGH Z
RN
1
1
0
STATE
I
N
MNEMONIC
OPERATION
#2
C
7
LONG
SKIP
TAKEN: RP + 1 → RP
S1#1
C
C
LONG
SKIP
S1#1
C
D
#2
C
S1#1
X, P → T; 0 → MIE
1 → P; 2 → X
THE FOLLOWING ARE ALL LINKED INSTRUCTIONS “68” PRECEEDS ALL OP CODES, SO THERE IS A DUPLICATE FETCH
S1
0
0
STPC
S1
0
1
DTC
STOP COUNTER CLOCK;
0 → ÷ 32 PRESCALER
HIGH Z
R0
1
1
0
CNTR - 1 → CNTR
HIGH Z
R1
1
1
0
26
CDP1805AC, CDP1806AC
TABLE 2. CONDITIONS ON DATA BUS AND MEMORY ADDRESS LINES DURING ALL MACHINE STATES (Continued)
DATA
BUS
MEMORY
ADDRESS
MRD
MWR
N
LINES
CNTR - 1 ON EF2 AND TPA
HIGH Z
R2
1
1
0
SCM2
CNTR - 1 ON EF2 0 TO 1
HIGH Z
R3
1
1
0
4
SPM1
CNTR - 1 ON EF1 AND TPA
HIGH Z
R4
1
1
0
0
5
SCM1
CNTR - 1 ON EF1 0 TO 1
HIGH Z
R5
1
1
0
S1
0
6
LDC
CNTR STOPPED: D → CH,
CNTR; 0 → CI
CNTR RUNNING: D → CH
D
R6
1
1
0
S1
0
7
STM
CNTR - 1 ON TPA ÷ 32
HIGH Z
R7
1
1
0
S1
0
8
GEC
CNTR → D
CNTR
R8
1
1
0
S1
0
9
ETQ
IF CNTR THRU 0: Q → Q
HIGH Z
R9
1
1
0
S1
0
A
XIE
1 → XIE
HIGH Z
RA
1
1
0
S1
0
B
XID
0 → XIE
HIGH Z
RB
1
1
0
S1
0
C
CIE
1 → CIE
HIGH Z
RC
1
1
0
S1
0
D
CID
0 → CIE
HIGH Z
RD
1
1
0
S1#1
2
0-F
DBNZ
RN - 1 → RN
HIGH Z
RN
1
1
0
#2
2
0-F
DBNZ
MRP → B; RP + 1 → RP
MRP
RP
0
1
0
#3
2
0-F
DBNZ
TAKEN: B → RP.1, MRP →
RP.0
NOT TAKEN: RP + 1 → RP
M(RP + 1)
RP + 1
0
1
0
S1
3
E
BCI
TAKEN: MRP → RP.0;
0 → CI
NOT TAKEN: RP + 1 → RP
MRP
RP
0
1
0
S1
3
F
BXI
TAKEN: MRP → RP.0
NOT TAKEN: RP + 1 → RP
MRP
RP
0
1
0
S1#1
6
0-F
RLXA
MRX → B, RX + 1 → RX
MRX
RX
0
1
0
#2
6
0-F
RLXA
B → T; MRX → B; RX + 1 → RX
M(RX + 1)
RX + 1
0
1
0
#3
6
0-F
RLXA
B, T → RN.0, RN.1
HIGH Z
RN
1
1
0
S1#1
7
4
DADC
MRX + D + DF → DF, D
MRX
RX
0
1
0
#2
7
4
DADC
DECIMAL ADJUST → DF, D
HIGH Z
RD
1
1
1
S1#1
7
6
DSAV
RX - 1 → RX
HIGH Z
RP
1
1
0
#2
7
6
DSAV
T → MRX; RX - 1 → RX
T
RX - 1
1
0
0
#3
7
6
DSAV
D → MRX; RX - 1 → RX
SHIFT D RIGHT WITH CARRY
D
RX - 2
1
0
0
#4
7
6
DSAV
D → MRX
D
RX - 3
1
0
0
S1#1
7
7
DSMB
D - MRX - (NOT DF) → DF, D
MRX
RX
0
1
0
#2
7
7
DSMB
DECIMAL ADJUST → DF, D
HIGH Z
RP
1
1
0
S1#1
7
C
DACI
MRP + D + DF → DF, D;
RP + 1 → RP
MRP
RP
0
1
0
#2
7
C
DACI
DECIMAL ADJUST → DF, D
HIGH Z
RP + 1
1
1
0
S1#1
7
F
DSBI
D - MRP - (NOT DF) → DF, D;
RP + 1 → RP
MRP
RP
0
1
0
STATE
I
N
MNEMONIC
S1
0
2
SPM2
S1
0
3
S1
0
S1
OPERATION
27
CDP1805AC, CDP1806AC
TABLE 2. CONDITIONS ON DATA BUS AND MEMORY ADDRESS LINES DURING ALL MACHINE STATES (Continued)
DATA
BUS
MEMORY
ADDRESS
MRD
MWR
N
LINES
DECIMAL ADJUST → DF, D
HIGH Z
RP + 1
1
1
0
SCAL
RN.0, RN.1 → T, B
HIGH Z
RN
1
1
0
0-F
SCAL
T→ MRX RX - 1 → RX
RN.0
RX
1
0
0
8
0-F
SCAL
B → MRX RX - 1 → RX
RN.1
RX - 1
1
0
0
#4
8
0-F
SCAL
RP.0, RP.1 → T, B
HIGH Z
RP
1
1
0
#5
8
0-F
SCAL
B, T → RN.1, RN.0
HIGH Z
RN
1
1
0
#6
8
0-F
SCAL
MRN → B; RN + 1 → RN
MRP
RP
0
1
0
#7
8
0-F
SCAL
B → T; MRN → B; RN + 1 → RN
M(RP + 1)
RP + 1
0
1
0
#8
8
0-F
SCAL
B, T → RP.0, RP.1
HIGH Z
RP
1
1
0
S1#1
9
0-F
SRET
RN.0, RN.1 → T, B
HIGH Z
RN
1
1
0
#2
9
0-F
SRET
RX + 1 → RX
HIGH Z
RX
1
1
0
#3
9
0-F
SRET
B, T → RP.1, RP.0
HIGH Z
RP
1
1
0
#4
9
0-F
SRET
MRX → B; RX + 1 → RX
M(RX + 1)
RX + 1
0
1
0
#5
9
0-F
SRET
B → T; MRX → B
M(RX + 1
RX + 2
0
1
0
#6
9
0-F
SRET
B, T → RN.0, RN.1
HIGH Z
RN
1
1
0
S1#1
A
0-F
RSXD
RN.0, RN.1 → T, B
HIGH Z
RN
1
1
0
#2
A
0-F
RSXD
T → MRX; RX - 1 → RX
RN.0
RX
1
0
0
#3
A
0-F
RSXD
B → MRX; RX - 1 → RX
RN.1
RX - 1
1
0
0
S1#1
B
0-F
RNX
RN.0, RN.1 → T, B
HIGH Z
RN
1
1
0
#2
B
0-F
RNX
B, T → RX.1, RX.0
HIGH Z
RX
1
1
0
S1#1
C
0-F
RLDI
MRP → B; RP + 1 → RP
MRP
RP
0
1
0
#2
C
0-F
RLDI
B → T; MRP → B; RP + 1 → RP
M(RP + 1)
RP + 1
0
1
0
#3
C
0-F
RLDI
B, T → RN.0, RN.1;`
RP + 1 → RP
HIGH Z
RN
1
1
0
S1#1
F
4
DADD
MRX + D → DF; D
MRX
RX
0
1
0
#2
F
4
DADD
DECIMAL ADJUST → DF, D
HIGH Z
RP
1
1
0
S1#1
F
7
DSM
D - MRX → DF, D
MRX
RX
0
1
0
#2
F
7
DSM
DECIMAL ADJUST → DF, D
HIGH Z
RP
1
1
0
S1#1
F
C
DADI
MRP + D → DF, D;
RP + 1 → RP
MRP
RP
0
1
0
#2
F
C
DADI
DECIMAL ADJUST → DF, D
HIGH Z
RP + 1
1
1
0
S1#1
F
F
DSMI
D - MRP → DF, D
RP + 1 → RP
MRP
RP
0
1
0
#2
F
F
DSMI
DECIMAL ADJUST → DF, D
HIGH Z
RP + 1
1
1
0
STATE
I
N
MNEMONIC
#2
7
F
DSBI
S1#1
8
0-F
#2
8
#3
OPERATION
NOTE:
20. Data bus floats for first 2-1/2 clocks of the nine clock initialization cycle; all zeros for remainder of cycle.
28
CDP1805AC, CDP1806AC
INSTRUCTION SUMMARY
N
0
0
1
2
3
4
5
6
7
IDL
8
INC
2
DEC
BR
BQ
BZ
BDF
B1
B2
B3
B4
SKP
4
LDA
5
STR
6
IRX
7
RET
OUT
DIS
LDXA
STXD
ADC
SDB
SHRC
SMB
SAV
E
F
BNQ
BNZ
BNF
BN1
BN2
BN3
BN4
SDBI
SHLC
SMBI
LSKP LBNQ LBNZ
LBNF
LSIE
LSQ
LSZ
LSDF
ANI
XRI
ADI
SDI
SHL
SMI
ETQ
XIE
XID
CIE
CID
-
-
-
-
-
-
-
BCI
BXI
-
-
-
DACI
-
-
DSBI
-
-
-
DADI
-
-
DSMI
A
PLO
B
PHI
LBQ
LBZ
LBDF
NOP
LSNQ LSNZ
LSNF
D
SEP
E
SEX
OR
AND
XOR
INP
ADCI
GHI
LDX
D
SEQ
9
F
C
REQ
GLO
LBR
B
†
8
C
A
LDN
1
3
9
ADD
SD
SHR
SM
LDI
MARK
ORI
‘68’ LINKED OPCODES (DOUBLE FETCH)
0
STPC
DTC
SPM2 SCM2 SPM1 SCM1
LDC
STM
2
3
DBNZ
-
-
-
-
-
-
-
-
6
7
GEC
RLXA
-
-
-
-
DADC
-
DSAV DSMB
-
8
SCAL
9
SRET
A
RSXD
B
RNX
C
RLDI
F
-
-
-
-
DADD
-
-
DSM
†‘68’ is used as a linking OPCODE for the double fetch instructions.
29
-
CDP1805AC, CDP1806AC
Operating and Handling Considerations
Handling
Input Signals
All inputs and outputs of Intersil CMOS devices have a network for electrostatic protection during handling.
Operating
To prevent damage to the input protection circuit, input signals should never be greater than VDD nor less than VSS.
Input currents must not exceed 10mA even when the power
supply is off.
Operating Voltage
Unused Inputs
During operation near the maximum supply voltage limit,
care should be taken to avoid or suppress power supply
turn-on and turn-off transients, power supply ripple, or
ground noise; any of these conditions must not cause VDD VSS to exceed the absolute maximum rating.
A connection must be provided at every input terminal. All
unused input terminals must be connected to either VDD or
VSS, whichever is appropriate.
Output Short Circuits
Shorting of outputs to VDD or VSS may damage CMOS
devices by exceeding the maximum device dissipation.
All Intersil U.S. products are manufactured, assembled and tested utilizing ISO9000 quality systems.
Intersil Corporation’s quality certifications can be viewed at www.intersil.com/design/quality
Intersil products are sold by description only. Intersil Corporation reserves the right to make changes in circuit design, software and/or specifications at any time without
notice. Accordingly, the reader is cautioned to verify that data sheets are current before placing orders. Information furnished by Intersil is believed to be accurate and
reliable. However, no responsibility is assumed by Intersil or its subsidiaries for its use; nor for any infringements of patents or other rights of third parties which may result
from its use. No license is granted by implication or otherwise under any patent or patent rights of Intersil or its subsidiaries.
For information regarding Intersil Corporation and its products, see www.intersil.com
30