ZILOG Z86L7808PSC, Z86L7808SSC Datasheet

DS97LVO0701 2-1

1

P

RODUCT

S

PECIFICATION

Z86L78

1

IR/L

OW

-V

OLTAGE

M

ICROCONTROLLER

FEATURES

■

Low Power Consumption: 40 mW (Typical)

■

Three Standby Modes (Typical)
– STOP - 2 µ A
– HALT - 0.8 mA
– Low V oltage (<V

Lv

)

■

Programmable Watch-Dog/Power-On Reset Circuits

■

All Digital Inputs are CMOS Levels

■

Five Priority Interrupts
– Three External
– Two Assigned to Counter/Timers

■

Two Independent Comparators with Programmable
Interrupt Polarity

■

On-Chip Oscillator that Accepts a Crystal, Ceramic
Resonator, LC, RC (Mask Selectable), or External Clock
Drive

■

Mask Selectable Option to Enable 32 kHz Crystal
Operation

■

Special Architecture to Automate Both Generation and
Reception of Complex Pulses or Signals:

– One Programmable 8-Bit Counter/Timer with Two

Capture Registers

– One Programmable 16-Bit Counter/Timer with

One Capture Register

– Programmable Input Glitch Filter for Pulse

Reception

■

Mask-Selectable 200 KOhm Pull-Ups on Ports 0, 2, 3:
– All Eight Port 2 Bits Individually Selected
– Pull-Ups Automatically Disabled Upon Selecting

an Output.

GENERAL DESCRIPTION

Zilog's Z86L78 is a low-voltage microcontroller, a member
of the IR (Infrared) Family, with 16 KB of ROM and 493
bytes of general-purpose RAM. Manufactured in CMOS
technology and offered in 20-pin DIP or SOIC styles pack­ages, this cost-effective, low power consumption ROM­based device offers fast execution, efficient use of memo­ry, sophisticated interrupts, input/output bit manipulation
capabilities, automated pulse generation/reception, and
easy hardware/software system expansion.

The Z86L78 architecture is based on Zilog's 8-bit micro­controller core, with an Expanded Register File to allow ac­cess to register mapped peripherals, I/O circuits, and pow­erful counter/timer circuitry. The Z86L78 offers a flexible

I/O scheme, an efficient register and address space struc­ture, and a number of ancillary features that are useful in
many consumer, automotive, computer peripheral, and
battery operated hand-held applications.

For applications demanding powerful I/O capabilities, the
Z86L78 provides 16 pins dedicated to input and output.
These lines are grouped into three ports, which are config­urable under software control to provide timing, status sig­nals and parallel I/O.

There are four basic address spaces available to support a
wide range of configurations: Program Memory, Register
File, Expanded Register File, and Extended Data RAM.

Par t

ROM
(KB)

RAM*

(Bytes) I/O

Voltage

Range

Z86L78 16 493 16 2.0V to 3.9V

Note: *General-Purpose

Z86L78
IR/Low-Voltage Microcontroller Zilog

2-2 DS97LVO0701

GENERAL DESCRIPTION (Continued)

The Register File is composed of 256 bytes of RAM, and it
includes four I/O port registers, 16 control and status reg­isters and the rest are General-Purpose registers. The Ex­tended Data RAM adds 256 bytes of usable general-pur­pose registers. The Expanded Register File consists of
two additional register groups (F and D).

To unburden the system from coping with real-time tasks,
such as generating complex waveforms or receiving and
demodulating complex waveform/pulses, the Z86L78 of­fers an innovative intelligent counter/timer architecture
with 8-bit and 16-bit counter/timers (Figure 1). Additionally,
the Z86L78 features a large number of user-selectable
modes, and two on-board comparators to process analog
signals with separate reference voltages (Figure 2).

Notes: Signals with a preceding front slash, "/", are active

Low, for example, B//W (WORD is active Low); /B/W
(BYTE is active Low, only).

Power connections follow conventional descriptions be­low:

Connection Circuit Device

Power V

CC

V

DD

Ground GND V

SS

Figure 1. Counter/Timer Block Diagram

HI16

LO16

16-Bit

T16

TC16H

TC16L

HI8 LO8

And/Or

Logic

Clock

Divider

Glitch

Filter

Edge
Detect
Circuit

8-Bit

T8

TC8H

TC8L

8

8

16

8

Input

SCLK

1

2

48

Timer 16

Timer 8/16

Timer 8

8

8

8

8

8

Z86L78

Zilog IR/Low-Voltage Microcontroller

DS97LVO0701 2-3

1

Figure 2. Functional Block Diagram

Port 0

P00

P07

P20
P21
P22
P23
P24
P25
P26
P27

P31
P32
P33

Port 3

Port 2

Register File

256 x 8-Bit

ROM

16K x 8

Z8 Core

Register Bus

Internal

Address Bus

Internal Data Bus

Extended

Register

File

Extended

Register Bus

Counter/Timer 8

8-Bit

Counter/Timer 16

16-Bit

Machine

Timing

&

Instruction

Control

Power

XTAL2

VDD
VSS

P34
P35
P36

256 x 8-Bit

I/O Bit

Programmable

Extended Data RAM

Two Analog

Comparators

Interrupt Control

XTAL1

Z86L78
IR/Low-Voltage Microcontroller Zilog

2-4 DS97LVO0701

PIN DESCRIPTION

Figure 3. 20-Pin DIP/SOIC Pin Assignments

P24
P25
P26
P27

VDD
XTAL2
XTAL1

P31
P32
P00

P23
P22
P21
P20
VSS
P36
P35
P34
P33
P07

11

Z86L78

DIP/SOIC

1

10 20

Table 1. 20-Pin DIP and SOIC Pin Identification

Pin No. Symbol Direction Description

10 P00 Input/Output Port 0 is Nibble

Programmable.
11 P07 Input/Output
17 P20 Input/Output Port 2 pins are individually

configurable as input or

output
18 P21 Input/Output
19 P22 Input/Output
20 P23 Input/Output

1 P24 Input/Output
2 P25 Input/Output
3 P26 Input/Output
4 P27 Input/Output
8 P31 Input IRQ2/Modulator input

9 P32 Input IRQ0
12 P33 Input IRQ1
13 P34 Output T8 output
14 P35 Output T16 output
15 P36 Output T8/T16 output

7 XTAL1 Input Crystal, Oscillator Clock

6 XTAL2 Output Crystal, Oscillator Clock

5V

DD

Power Supply

16 V

SS

Ground

Z86L78

Zilog IR/Low-Voltage Microcontroller

DS97LVO0701 2-5

1

ABSOLUTE MAXIMUM RATINGS

Stresses greater than those listed under Absolute Maxi­mum Ratings may cause permanent damage to the de­vice. This is a stress rating only; operation of the device at
any condition above those indicated in the operational sec­tions of these specifications is not implied. Exposure to ab­solute maximum rating conditions for an extended period
may affect device reliability.

STANDARD TEST CONDITIONS

The characteristics listed below apply for standard test
conditions as noted. All voltages are referenced to
Ground. Positive current flows into the referenced pin (Fig­ure 4).

CAPACITANCE

T

A

= 25 ° C, V

CC

= GND = 0V, f = 1.0 MHz, unmeasured pins returned to Ground.

Symbol Description Min Max Units

V

CC

Supply V oltage (*) –0.3 +7.0 V

T

STG

Storage Temp. –65 ° +150 ° C

T

A

Oper. Ambient
Temp.

†C

Note:

* Voltage on all pins with respect to Ground.
† See Ordering Information.

Figure 4. Test Load Diagram

From Output

Under Test

150 pFI

Parameter Min Max

Input capacitance 0 12 pF
Output capacitance 0 12 pF
I/O capacitance 0 12 pF

Z86L78
IR/Low-Voltage Microcontroller Zilog

2-6 DS97LVO0701

DC ELECTRICAL CHARACTERISTICS

Preliminary

T

A

= 0 ° C to +70 ° C

Typical

Sym Parameter

V

CC

Min Max @ 25 ° C Units Conditions Notes

Max Input
Voltage

2.0V

3.9V

7
7

VVI

IN

250 µ A

I

IN

250 µ A

V

CH

Clock Input
High V oltage

2.0V

3.9V

0.9 V

CC

0.9 V

CC

V

CC

+ 0.3

V

CC

+ 0.3

VVDriven by External

Clock Generator
Driven by External
Clock Generator

V

CL

Clock Input
Low V oltage

2.0V

3.9V

V

SS

-0.3

V

SS

-0.3

0.2 V

CC

0.2 V

CC

VVDriven by External

Clock Generator
Driven by External
Clock Generator

V

IH

Input High
Voltage

2.0V

3.9V

0.7 V

CC

0.7 V

CC

V

CC

+ 0.3

V

CC

+ 0.3

1.3

2.5

V
V

V

IL

Input Low Voltage 2.0V

3.9V

V

SS

– 0.3

V

SS

– 0.3

0.2 V

CC

0.2 V

CC

0.5

0.9

V
V

V

OH1

Output High
Voltage

2.0V

3.9V

V

CC

– 0.4

V

CC

– 0.4

1.7

3.7

VVI

OH

= –0.5 mA

V

OH2

Output High
Voltage (P36,
P37)

2.0V

3.9V

0.7

0.7

VVI

OH

= –7 mA

V

OL1

Output Low
Voltage

2.0V

3.9V

0.4

0.4

0.2

0.1

VVI

OL

= 1.0 mA

I

OL

= <4.0 mA

V

OL2

Output Low
Voltage

2.0V

3.9V

0.8

0.8

0.3

0.5

VVI

OL

= 2.0 mA

3 Pin Max

V

RH

Reset Input
High V oltage

2.0V

3.9V

0.8 V

CC

0.8 V

CC

V

CC

V

CC

1.5

3.0

V
V

V

Rl

Reset Input
Low V oltage

2.0V

3.9V

VSS - 0.3
V

SS

- 0.3

0.2 V

CC

0.2 V

CC

0.5

0.9

V

OFFSET

Comparator
Input Offset
Voltage

2.0V

3.9V

25
25

10
10

mV
mV

I

IL

Input Leakage 2.0V

3.9V

-1

-1

1
1

<1
<1

µAµAVIN = OV, V

CC

VIN = OV, V

CC

I

OL

Output Leakage 2.0V

3.9V

-1

-1

1
1

<1
<1

µAµAVIN = OV, V

CC

VIN = OV, V

CC

I

IR

Reset Input
Current

2.0V

3.9V

-45

-55

-20

-30

µA
µA

I

CC

Supply Current
(WDT Off)

2.0V

3.9V

2.0V

3.9V

10

15
100
300

4
10
10
10

mA
mA
mA
mA

@ 8.0 MHz
@ 8.0 MHz
@ 32 kHz
@ 32 kHz

4,5

Z86L78

Zilog IR/Low-Voltage Microcontroller

DS97LVO0701 2-7

1

TA = 0°C to +70°C

Typical

Sym Parameter

V

CC

Min Max @ 25°C Units Conditions Notes

I

CC1

Standby
Current
(WDT OFF)

2.0V

3.9V

2.0V

3.9V

3

5

2
4

1

4

0.8

2.5

mA

mA

mA

mA

HALT Mode
VIN=0V, V

CC

@ 8.0 MHz
HALT Mode
VIN=0V, V

CC

@ 8.0 MHz
Clock Divide-by-16
@ 8.0 MHz
Clock Divide-by-16
@ 8.0 MHz

1,2

I

CC2

Standby
Current
(WDT Off)

2.0V

3.9V

2.0V

3.9V

8

10

500

800

2

3

310

600

µA

µA

µA

µA

STOP Mode
VIN = 0V, V

CC

WDT is not Running
STOP Mode
VIN = 0V, V

CC

WDT is not Running
STOP Mode
VIN = 0V, V

CC

WDT is not Running
STOP Mode
VIN = 0V, V

CC

WDT is not Running

3,5

3,5

3,5

3,5

V

ICR

Input Common
Mode V oltage
Range

2.0V

3.9V

0
0

VCC - 1.0V
V

CC

- 1.0V

V
V

11

T

POR

Power-On
Reset

2.0V

3.9V

7.5

2.5

75
20

13

7

ms

ms

V

rf1

Voltage
Reference

1.8 2.0 V 8 MHz max 4

Notes:

1. GND = 0V

2. 2.0V to 3.9V

3. All outputs unloaded, I/O pins floating, inputs at rail.

4. CL1 = CL2 = 100 pF

5. Same as note [4] except inputs at V

CC

.

6. The Vrf1 increases as the temperature decreases.

7. Oscillator stopped

8. Two outputs at a time, independent to other outputs.

9. One at a time

10. 32 kHz clock driver input

11. For analog comparator, inputs when analog comparators are enabled.

Z86L78
IR/Low-Voltage Microcontroller Zilog

2-8 DS97LVO0701

AC CHARACTERISTICS

External I/O or Memory Read and Write Timing Diagram

Figure 5. External I/O or Memory Read/Write Timing

R//W

9

12

18

3

16

13

4

5

8 11

6

17

10

15

7

14

21

Port 0, /DM

Port 1

/AS

/DS

(Read)

Port 1

/DS

(Write)

A7 - A0 D7 - D0 IN

D7 - D0 OUTA7 - A0

19

20

Z86L78

Zilog IR/Low-Voltage Microcontroller

DS97LVO0701 2-9

1

AC CHARACTERISTICS

Preliminary
External I/O or Memory Read and Write Timing Table

T

A

= 0°C to +70°C

No Sym Parameter

V

CC

MIn Max Units Notes

1 TdA(AS) Address V alid to

/AS Rising Delay

2.0V

3.9V

55
55

ns
ns

2

2 TdAS(A) /AS Rising to Address

Float Delay

2.0V

3.9V

70
70

ns
ns

2

3 TdAS(DR) /AS Rising to Read

Data Required Valid

2.0V

3.9V

400
400

ns
ns

1,2

4 TwAS /AS Low Width 2.0V

3.9V

80
80

ns
ns

2

5 Td Address Float to /DS

Falling

2.0V

3.9V

0
0

ns
ns

6 TwDSR /DS (Read) Low Width 2.0V

3.9V

300
300

ns
ns

1,2

7 TwDSW /DS (Write) Low Width 2.0V

3.9V

165
165

ns
ns

1,2

8 TdDSR(DR) /DS Falling to Read

Data Required Valid

2.0V

3.9V

260
260

ns
ns

1,2

9 ThDR(DS) Read Data to

/DS Rising Hold Time

2.0V

3.9V

0
0

ns
ns

2

10 TdDS(A) /DS Rising to Address

Active Delay

2.0V

3.9V

85
95

ns
ns

2

11 TdDS(AS) /DS Rising to /AS

Falling Delay

2.0V

3.9V

60
70

ns
ns

2

12 TdR/W(AS) R//W Valid to /AS

Rising Delay

2.0V

3.9V

70
70

ns
ns

2

13 TdDS(R/W) /DS Rising to

R//W Not Valid

2.0V

3.9V

70
70

ns
ns

2

14 TdDW(DSW) Write Data Valid to /DS

Falling (Write) Delay

2.0V

3.9V

80
80

ns
ns

2

15 TdDS(DW) /DS Rising to Write

Data Not Valid Delay

2.0V

3.9V

70
80

ns
ns

2

16 TdA(DR) Address Valid to Read

Data Required Valid

2.0V

3.9V

475
475

ns
ns

1,2

17 TdAS(DS) /AS Rising to /DS Falling

Delay

2.0V

3.9V

100
100

ns
ns

2

18 TdDM(AS) /DM Valid to /AS

Falling Delay

2.0V

3.9V

55
55

ns
ns

2

19 TdDS(DM) /DS Rise to

/DM V alid Delay

2.0V

3.9V

70
70

ns
ns

20 ThDS(A) /DS Rise to Address

Valid Hold Time

2.0V

3.9V

70
70

ns
ns

Notes:

1. When using extended memory timing add 2 TpC.

2. Timing numbers given are for minimum TpC.

Standard Test Load

All timing references use 0.9 V

CC

for a logic 1 and 0.1 VCC for a logic 0.

Z86L78
IR/Low-Voltage Microcontroller Zilog

2-10 DS97LVO0701

AC CHARACTERISTICS

Additional Timing Diagram

Figure 6. Additional Timing

Clock

1

3

4

8

2 2 3

T

IRQ

IN

N

6

5

7 7

Clock

Setup

10

9

Stop

Mode

Recovery

Source

11

Z86L78

Zilog IR/Low-Voltage Microcontroller

DS97LVO0701 2-11

1

AC CHARACTERISTICS

Preliminary
Additional Timing Table

TA = 0°C to +70°C

8.0 MHz

No Symbol Parameter

V

CC

Min Max Units Notes

1 TpC Input Clock Period 2.0V

3.9V

121
121

DC
DC

ns
ns

1
1

2 TrC,TfC Clock Input Rise

and Fall Times

2.0V

3.9V

25
25

ns
ns

1
1

3 TwC Input Clock Width 2.0V

3.9V

37
37

ns
ns

1
1

4 TwTinL Timer Input

Low Width

2.0V

3.9V

100

70

ns
ns

1
1

5 TwTinH Timer Input

High Width

2.0V

3.9V

3TpC
3TpC

1
1

6 TpTin Timer Input Period 2.0V

3.9V

8TpC
8TpC

1
1

7 TrTin,TfTin Timer Input Rise

and Fall Timers

2.0V

3.9V

100
100

ns
ns

1
1

8A TwIL Interrupt Request

Low Time

2.0V

3.9V

100

70

ns
ns

1,2
1,2

8B TwIL Int. Request

Low Time

2.0V

3.9V

5TpC
5TpC

1,3
1,3

9 TwIH Interrupt Request

Input High Time

2.0V

3.9V

5TpC
5TpC

1,2
1,2

10 Twsm Stop-Mode Recovery Width

Spec

2.0V

3.9V

2.0V

3.9V

12

12
5TpC
5TpC

ns
ns
ns
ns

5
5
4
4

11 Tost Oscillator Start-up Time 2.0V

3.9V

5TpC
5TpC

4
4

12 Twdt Watch-Dog Timer (5 ms)

Delay Time

2.0V

3.9V

10

5

75
20

ms
ms

(10 ms) 2.0V

3.9V

30

10

150

40

ms
ms

(15 ms) 2.0V

3.9V

50

20

300

80

ms
ms

(80 ms) 2.0V

3.9V

200

80

1200

320

ms
ms

Notes:

1. Timing Reference uses 0.9 V

CC

for a logic 1 and 0.1 VCC for a logic 0.

2. Interrupt request through Port 3 (P33-P31).

3. Interrupt request through Port 3 (P30).

4. SMR – D5 = 0

5. SMR – D5 =1

Z86L78
IR/Low-Voltage Microcontroller Zilog

2-12 DS97LVO0701

AC CHARACTERISTICS

Handshake Timing Diagrams

Figure 7. Input Handshake Timing

Data In

1

3

4

5 6

/DAV

(Input)

RDY

(Output)

Next Data In Valid

Delayed RDY

Delayed DAV

Data In Valid

2

Figure 8. Output Handshake Timing

Data Out

/DAV

(Output)

RDY

(Input)

Next Data Out Valid

Delayed RDY

Delayed DAV

Data Out Valid

7

8 9

10

11

Z86L78

Zilog IR/Low-Voltage Microcontroller

DS97LVO0701 2-13

1

AC CHARACTERISTICS

Preliminary
Handshake Timing Table

TA = 0°C to +70°C

8 MHz Data

No Symbol Parameter

V

CC

Min Max Direction

1 TsDI(DAV) Data In Setup Time 2.0V

3.9V

0
0

IN
IN

2 ThDI(DAV) Data In Hold Time 2.0V

3.9V

160
115

IN
IN

3 TwDAV Data Available Width 2.0V

3.9V

155
110

IN
IN

4 TdDAVI(RDY) DAV Falling to RDY

Falling Delay

2.0V

3.9V

160
115

IN
IN

5 TdDAVId(RDY) DAV Rising to RDY

Falling Delay

2.0V

3.9V

120

80

IN
IN

6 TdRDYO(DAV) RDY Rising to DAV

Falling Delay

2.0V

3.9V

0
0

IN
IN

7 TdDO(DAV) Data Out to DAV

Falling Delay

2.0V

3.9V

63
63

OUT
OUT

8 TdDAV0(RDY) DAV Falling to RDY

Falling Delay

2.0V

3.9V

0
0

OUT
OUT

9 TdRDY0(DAV) RDY Falling to DAV

Rising Delay

2.0V

3.9V

160
115

OUT
OUT

10 TwRD Y RDY Width 2.0V

3.9V

110

80

OUT
OUT

11 TdRDY0d(DAV) RDY Rising to DAV

Falling Delay

2.0V

3.9V

110

80

OUT
OUT

Notes:

Writing or reading the Extended Data RAM is accomplished by using LDE instruction only.

Z86L78
IR/Low-Voltage Microcontroller Zilog

2-14 DS97LVO0701

PIN FUNCTIONS

XTAL1 Crystal 1 (time-based input). This pin connects a

parallel-resonant crystal, ceramic resonator, LC, or RC
network or an external single-phase clock to the on-chip
oscillator input.

XTAL2 Crystal 2 (time-based output). This pin connects a
parallel-resonant, crystal, ceramic resonant, LC, or RC
network to the on-chip oscillator output.

Port 0 (P07 and 00). Port 0 is an 2-bit, bidirectional,
CMOS-compatible port. These two I/O lines are configured

under software control, and the output drivers are push­pull.

If one or both bits are needed for I/O operation, they must
be configured by writing to the Port 0 mode register. After
a hardware reset, Port 0 is configured as an input port.

An optional 200 KOhm pull-up is available as a mask op­tion on P07 and P00.

These pull-ups are disabled when configured (bit by
bit) as outputs.

Figure 9. Port 0 Configuration

Z86L78

MCU

1

1

Port 0

OEN

Out

In

PAD

200 kΩ

Mask
Option

Z86L78

Zilog IR/Low-Voltage Microcontroller

DS97LVO0701 2-15

1

Port 2 (P27-P20). Port 2 is an 8-bit, bidirectional, CMOS-

compatible I/O port. These eight I/O lines can be indepen­dently configured under software control as inputs or out­puts. Port 2 is always available for I/O operation. A mask
option is available to connect eight 200 KOhm (±50%) pull­up resistors on this port. Bits programmed as outputs are
globally programmed as either push-pull or open-drain.

The Z86L78 wakes up with the eight bits of Port 2 config­ured as inputs with open-drain outputs.

Port 2 also has an 8-bit input OR and an AND gate which
can be used to wake up the part (Figure 33). P20 can be
programmed to access the edge selection circuitry (Figure

10).

Figure 10. Port 2 Configuration

Open-Drain

OEN

Out

In

Pad

VCC

200 kΩ

Mask
Option

Z86L78

MCU

Port 2 (I/O)

Z86L78
IR/Low-Voltage Microcontroller Zilog

2-16 DS97LVO0701

PIN FUNCTIONS (Continued)

Port 3 (P37-P31). Port 3 is a 6-bit, CMOS-compatible

three fixed input and four fixed output port. Port 3 and can
be configured under software control for Input/Output, In­terrupt, and output from the counter/timers. P31, P32, and
P33 are standard CMOS inputs. Outputs P34, P35 are
push-pull or open-drain depending on P3M D0. P36 is
push-pull.

Two on-board comparators process analog signals on P31
and P32 with reference to the voltage on P33. The analog

function is enabled by programming the Port 3 Mode Reg­ister (bit 1). P31 and P32 are programmable as rising, fall­ing, or both edge triggered interrupts (IRQ register bits 6
and 7). P33 is the comparator reference voltage inputs.
Access to the edge detection circuit is through P31 or P20.
P33 will be in common to both comparators.

Port 3 provides output for each of the counter/timers and
the AND/OR Logic. Control is performed by programming
bits D5-D4 of CTRI, bit 0 of CTR0 and bit 0 of CTR2.

Comparator Inputs. In Analog Mode, Port 3, P31 and P32
have a comparator front end. The comparator reference
voltages are on P33. The internal P33 register and its cor­responding IRQ1 is connected to the Stop-Mode Recovery
source selected by the SMR. In this mode, any of the Stop­Mode Recovery sources can be used to toggle the P33 bit
or generate IRQ1. In digital mode, P33 can be used as a
Port 3 register input or IRQ1 for P33 (Figure 9).

Notes: Comparators are powered down by entering STOP
Mode. For P33-P31 to be used as a STOP-mode recovery
source, these inputs must be placed into digital mode.

Comparator Outputs. Comparator output of COMP1 can
be programmed to output on P34 through the PCON reg­ister (Figure 8).

/RESET (Input, active Low). Initializes the MCU. Reset is
accomplished either through Power-On, Watch-Dog Tim­er; Stop-Mode Recovery, and Low Voltage detection. Dur­ing Power-On Reset and Watch-Dog Timer Reset, the in­ternally generated reset drives the internal reset Low for
the POR time.

Table 2. Port 3 Pin Assignments

Pin I/O C/T Comp. Int. P0 HS P1 HS P2 HS Ext

Pref1 IN RF1
P31 IN ISP AN1 IRQ2 D/R
P32 IN AN2 D/R
P33 IN RF2 IRQ1 D/R
P34 OUT T8 A01 R/D DM
P35 OUT T16 R/D
P36 OUT T8/16 R/D
P00 I/O

Notes:

HS = Handshake Signals
D = /DAV
R = RDY

Z86L78

Zilog IR/Low-Voltage Microcontroller

DS97LVO0701 2-17

1

Figure 11. Port 3 Configuration

P34 OUT

**P37

P32

+

-

P33

0 = P34, P37 Standard Output
1 = P34, P37 Comparator Output

PCON

D0

P31

+

-

P33

**P37

PAD

P34

PAD

*

T8

P34 OUT

0 Normal Control
1 8-bit Timer output active

CTR0

D0

Counter/Timer

Notes:

* Reset condition.
** Available only on 40-pin versions of the L7X family.

P34 OUT

Z86L78
IR/Low-Voltage Microcontroller Zilog

2-18 DS97LVO0701

PIN FUNCTIONS (Continued)

Program execution begins at location 000CH, 5-10 TpC
cycles after the RST is asserted. For Power-On Reset, the
typical reset output time is 5 ms.

Note: The Z86L78 does not reset WDTMR, SMR, P2M,
or P3M registers on a Stop-Mode Recovery operation.

Figure 12. Port 3 Configuration

Port 3
(I/O or Handshake)

Z86LXX

MCU

Pref1
P31

P32
P33

P34
P35

P36
P37

Note:

P31, 32, 33 have a 200 KΩ
mask option called Mask
option 3 similar to Mask
options 1 and 2.

200 KΩ

Mask
Option

D1

R247 = P3M

P31 (AN1)

P32 (AN2)

P33 (REF2)

From Stop-Mode
Recovery Source

1 = Analog
0 = Digital

IRQ2, TIN, P31 Data Latch

IRQ0, P32 Data Latch

IRQ1, P33 Data Latch

DIG.

AN.

-

+

-

+

Pref1*

Z86L78

Zilog IR/Low-Voltage Microcontroller

DS97LVO0701 2-19

1

Figure 13. Port 3 Configuration

VDD

Out 34

T8_Out

CTR0, D0

Pad

Out 35

T16_Out

CTR2, D0

Out 36

T8/16_Out

CTR1, D6

MUX

MUX

MUX

P34

VDD

Pad

P35

VDD

Pad

P36

Z86L78
IR/Low-Voltage Microcontroller Zilog

2-20 DS97LVO0701

FUNCTIONAL DESCRIPTION

The Z86L78 incorporates special features to enhance the
standard Z8 core architecture to provide the user with in­creased design flexibility in the areas of consumer and bat­tery operated applications.

Reset. The device is reset in one of the following condi­tions:

1. Power-On Reset

2. Watch-Dog Timer

3. Stop-Mode Recovery Source

4. Low Voltage Detection
Program Memory. The Z86L78 addresses up to 16 KB of

internal program memory (Figure 14). The first 12 bytes of
program memory are reserved for the interrupt vectors.
These locations contain five 16-bit vectors that correspond
to the five available interrupts. Addresses to 16K consist of
on-chip mask-programmed ROM.

Figure 14. Program Memory Map

11

10

9

8

7

6

5

4

3

2

1

0

Not Addressable

Location of

First Byte of

Instruction

Executed

After RESET

Interrupt

Vector

(Lower Byte)

Interrupt

Vector

(Upper Byte)

Reserved

IRQ4

IRQ4

IRQ3

IRQ3

IRQ2

IRQ2

IRQ1

IRQ1

IRQ0

IRQ0

Reserved

65535

On-Chip

ROM

16384

256 bytes internal data RAM

65280

Reset Start Address

12

Z86L78

Zilog IR/Low-Voltage Microcontroller

DS97LVO0701 2-21

1

RAM. The Z86L78 has 512-bytes of RAM and 256 bytes

make-up the Register file. The remaining 256 bytes make
up the Extended Data RAM.

Extended Data RAM. The Extended Data RAM occupies
the address range. FF00H-FFFFH (256 bytes). Accessing
the Extended Data RAM is accomplished by using LDE in­struction only.

Note: The Extended Data RAM cannot be used as Stack
or instructions/code memory.

Expanded Register File (ERF). The standard Z8 register
file has been expanded to allow for additional system con­trol registers, and for mapping of additional peripheral de­vices along with I/O ports into the register address area.
The Z8 register address space R0 through R15 has been
implemented as 16 groups of 16 registers per group.
These register groups are known as the Expanded Regis­ter File (ERF). Bits 7-4 of register RP select the working
register group. Bits 3-0 of register RP select the expanded
register group (Figure 16).

The upper nibble of the register pointer (Figure 18) selects
which group of 16 bytes in the register file, out of the full
256 bytes, will be accessed. The lower nibble selects the
expanded register file bank and, in the case of the Z86L78,
Banks F and D are implemented. A 0H in the lower nibble
will allow the normal register file to be addressed, but any
other value from 1H to FH will exchange the lower 16 reg­isters in favor of an expanded register group of 16 regis­ters.

For example:
Z86L78: (See Figure 17)
R253 RP = 00H R0 = Port 0

R1 = Port 1
R2 = Port 2

R3 = Port 3
But if:
R253 RP = 0DH R0 = CTRL0

R1 = CTRL1

R2 = CTRL2

R3 = Reserved
The counter/timers are mapped into ERF group D. Access

is easily done using the following example:
LD RP, #0DH Select ERF D for access and register Bank

0 as the working register group
LD R0,#xx access CTRL0
LD1, #xx access CTRL1
LDRP, #7DH Select expanded register group (ERF) group

D for access and register Bank 7 as the working reg-

ister bank
LDR1, 2 CTRL2 → register 71H

Figure 15. Register Pointer Register

D7 D6 D5 D4 D3 D2 D1 D0

Expanded Register
File Pointer

Working Register
Pointer

R253 RP

Default Setting After Reset = 0000 0000

Z86L78
IR/Low-Voltage Microcontroller Zilog

2-22 DS97LVO0701

Figure 16. Expanded Register File Architecture

7

6543210

Working Register

Group Pointer

Expanded Register

Group Pointer

FF
FO

7F

0F

00

Z8 Register File**

REGISTER POINTER

FF
FE
FD
FC
FB
FA
F9

F8
F7
F6

F5
F4
F3
F2
F1
F0

SPL
SPH
RP
FLAGS
IMR
IRQ
IPR
P01M
P3M
P2M

U
U

0
U
0

0
U
0

0

1

(F) 0F
(F) 0E
(F) 0D
(F) 0C

(F) 0B

(F) 0A
(F) 09
(F) 08
(F) 07
(F) 06
(F) 05
(F) 04
(F) 03
(F) 02
(F) 01
(F) 00

WDTMR

SMR

U
U
0

U

U
0
U
1
0

1

U
U

0
U
U

0

U

0

0

1

U
U

0
U
U

0
U

0

0
1

U
U

0
U
U
0
U
1
0
1

U
U
0

U

U
0
U

1
0
1

U
U
0
U

U
0
U
0
0

1

U
U
0

U

U
0
U

1
0
1

UUU 0 1

101

001000U0

REGISTER**

EXPANDED REG. GROUP (F)

RESET CONDITION

REGISTER**

Z8® STANDARD CONTROL REGISTERS

RESET CONDITION

D7 D6

D5 D4

D3 D2 D1

D0

Reserved

*
*

*

†

Reserved
SMR2
Reserved

Reserved
Reserved
Reserved
Reserved
Reserved

Reserved

UUUUU

UU

U

UUUUUUUU
UUU

UUUUU

UUUUUUU

U

0

0

000000

0U

U

00

00

0

Reserved
Reserved
Reserved
Reserved
Reserved
PCON

U

0

*

00 00UU

UU

UU

UUUUUU

UU

UU

UUU

U

UUU

UUU

UU

REGISTER**

EXPANDED REG. GROUP (0)

RESET CONDITION

(0) 03

P3

(0) 02

P2
(0) 01 P1
(0) 00

P0

*
*

Reserved
Reserved

Reserved
Reserved

Reserved

U0U00 0UU

EXPANDED REG. GROUP (D)

REGISTER**

(D) 0C

(D) 0B
(D) 0A

(D) 09

(D) 08
(D) 07
(D) 06
(D) 05
(D) 04
(D) 03
(D) 02

Reserved
HI8
L08

HI16

L016
TC16H
TC16L
TC8H

TC8L
Reserved
CTR2

RESET CONDITION

U

UU

U

UUUUUUU
U
U
U

U

U
U
U

0

UUUUU

U

U

U

U

U

U

U

UUUUUU

U
U
U
U
U

U

U
U
U
U
U

U

UUU0

UUUU

U
U

U
U

UU
UUU
UUU

UUU

(D) 01 CTR1
(D) 00 CTR0

00UUUUU U

0

UUUUUU

Reserved

U

U

U

U

U

U

0

Notes:

U = Unknown
* Will not be reset with a Stop-Mode Recovery.
** All addresses are in Hexadecimal.
† Will not be reset with a Stop-Mode Recovery, except Bit 0.
0' L78 is undefined.

Z86L78

Zilog IR/Low-Voltage Microcontroller

DS97LVO0701 2-23

1

Register File. The register file (group 0) consists of four

I/O port registers, 236 general-purpose registers, and 16
control and status registers (R0-R3, R4-R239, and R240­R255, respectively), Plus two expanded registers groups
(Banks D and F). Instructions can access registers directly
or indirectly through an 8-bit address field. This allows a
short, 4-bit register address using the Register Pointer
(Figure 15). In the 4-bit mode, the register file is divided
into 16 working register groups, each occupying 16 contin­uous locations. The Register Pointer addresses the start­ing location of the active working register group. Note:

Registers E0-EF of Bank 0 are only accessed through
working registers and indirect addressing modes.

Stack. The Z86L78 internal register file is used for the

stack. An 8-bit Stack Pointer (R255) is used for the internal
stack that resides within the general-purpose registers
(R4-R239). SPH is used as a general-purpose register
only when using internal stacks. Note: Only the lower 256
bytes of RAM may be used for stack operations.

Note: When SPH is used as a general-purpose register
and Port 0 is in address mode, the contents of SPH will be
loaded into Port 0 whenever the internal stack is accessed.

Figure 17. Register Pointer

The upper nibble of the register file address
provided by the register pointer specifies
the active working-register group

r7r6r5r

4

R253

I/O Ports

Specified Working

Register Group

The lower nibble
of the register
file address
provided by the
instruction points
to the specified
register

r3r2r1r

0

Register Group 0

FF

Register Group 1

2F

1F

0F

00

10

20

F0

R15 to R4
R3 to R0

R15 to R0

R15 to R0

Z86L78
IR/Low-Voltage Microcontroller Zilog

2-24 DS97LVO0701

Counter/Timer Register Description

Expanded Register Group D

Register Description

HI8(D)%0B: Holds the captured data from the output of the

8-bit Counter/Timer0. This register is typically used to hold
the number of counts when the input signal is 1.

L08(D)%0A: Holds the captured data from the output of
the 8-bit Counter/Timer0. This register is typically used to
hold the number of counts when the input signal is 0.

HI16(D)%09: Holds the captured data from the output of
the 16-bit Counter/Timer16. This register holds the MS­Byte of the data.

L016(D)%08: Holds the captured data from the output of
the 16-bit Counter/Timer16. This register holds the LS­Byte of the data.

TC16H(D)%07: Counter/Timer2 MS-Byte Hold Register.

TC16L(D)%06: Counter/Timer2 LS-Byte Hold Register.

TC8H(D)%05: Counter/Timer8 High Hold Register.

TC8L(D)%04: Counter/Timer8 Low Hold Register.

(D)%0C Reserved

(D)%0B HI8
(D)%0A LO8
(D)%09 HI16
(D)%08 LO16
(D)%07 TC16H
(D)%06 TC16L
(D)%05 TC8H
(D)%04 TC8L
(D)%03 Reserved
(D)%02 CTR2
(D)%01 CTR1
(D)%00 CTR0

Field Bit Position Description

T8_Capture_HI 76543210 R

W

Captured Data

No Effect

Field Bit Position Description

T8_Capture_L0 76543210 RWCaptured Data

No Effect

Field Bit Position Description

T16_Capture_HI 76543210 RWCaptured Data

No Effect

Field Bit Position Description

T16_Capture_LO 76543210 RWCaptured Data

No Effect

Field Bit Position Description

T16_Data_HI 76543210 R/W Data

Field Bit Position Description

T16_Data_LO 76543210 R/W Data

Field Bit Position Description

T8_Level_HI 76543210 R/W Data

Field Bit Position Description

T8_Level_LO 76543210 R/W Data

Z86L78

Zilog IR/Low-Voltage Microcontroller

DS97LVO0701 2-25

1

CTR0 (D)00: Counter/Timer8 Control Register.

CTR0: Counter/Timer8 Control Register Description
T8 Enable. This field enables T8 when set (written) to 1.
Single/Modulo-N. When set to 0 (modulo-n), the counter

reloads the initial value when the terminal count is
reached. When set to 1 (single pass), the counter stops
when the terminal count is reached.

Time-Out. This bit is set when T8 times out (terminal count
reached). To reset this bit, a 1 should be written to this lo­cation. This is the only way to reset this status condition,
therefore, care should be taken to reset this bit prior to us­ing/enabling the counter/timers.

Note: Care must be taken when utilizing the OR or AND
commands to manipulate CTR0, bit 5 and CTR1, bits 0
and 1 (Demodulation Mode). These instructions use a
Read-Modify-Write sequence in which the current status
from the CTR0 and CTR1 registers will be ORed or ANDed
with the designated value and then written back into the
registers. Example: When the status of bit 5 is 1, a reset
condition will occur.

T8 Clock. Defines the frequency of the input signal to T8.
Capture_INT_Mask. Set this bit to allow interrupt when

data is captured into either LO8 or HI8 upon a positive or
negative edge detection in demodulation mode.

Counter_INT_Mask. Set this bit to allow interrupt when T8
has a time out.

P34_Out. This bit defines whether P34 is used as a normal
output pin or the T8 output.

Field Bit Position Value Description

T8_Enable 7------- R0*

1
0
1

Counter Disabled
Counter Enabled
Stop Counter
Enable Counter

Single/Modulo-N -6------ R/W 0

1

Modulo-N
Single Pass

Time-Out --5----- R0

1
0

1‘

No Counter Time-Out
Counter Time-Out Occurred
No Effect
Reset Flag to 0

T8_Clock ---43--- R/W 0 0

0 1
1 0
1 1

SCLK
SCLK/2
SCLK/4
SCLK/8

Capture_INT_MASK -----2-- R/W 0

1

Disable Data Capture Int.
Enable Data Capture Int.

Counter_INT_Mask ------1- R/W 0

1

Disable Time-Out Int.
Enable Time-Out Int.

P34_Out -------0 R/W 0*

1

P34 as Port Output*
T8 Output on P34

Note: *Indicates the value upon Power-On Reset

Z86L78
IR/Low-Voltage Microcontroller Zilog

2-26 DS97LVO0701

CTR1(D)%01: Controls the functions in common with the T8 and T16.

Field Bit Position Value Description

Mode 7------- R/W 0*

1

Transmit Mode
Demodulation Mode

P36_Out/Demodulator_Input -6------ R/W

0*

1
0

1

Transmit Mode
Port Output
T8/T16 Output
Demodulation Mode
P31
P20

T8/T16_Logic/Edge Detect --54---- R/W

00
01
10
11

00
01
10
11

Transmit Mode
AND
OR
NOR
NAND
Demodulation Mode
Falling Edge
Rising Edge
Both Edges
Reserved

Transmit_Submode/Glitch_Filter ----32-- R/W

00
01
10
11

00
01
10
11

Transmit Mode
Normal Operation
Ping-Pong Mode
T16_Out = 0
T16_Out = 1
Demodulation Mode
No Filter
4 SCLK Cycle
8 SCLK Cycle
16 SCLK Cycle

Initial_T8_Out/Rising_Edge ------1-

0
1

0
1
0
1

Transmit Mode
T8_OUT is 0 Initially
T8_OUT is 0 Initially
Demodulation Mode
No Rising Edge
Rising Edge Detected
No Effect
Reset Flag to 0

Initial_T16_Out/Falling_Edge -------0

R/W

R

W

0
1

0
1
0
1

Transmit Mode
T16_OUT is 1 Initially
T16_OUT is Initially
Demodulation Mode
No Falling Edge
Falling Edge Detected
No Effect
Reset Flag to 0

Z86L78

Zilog IR/Low-Voltage Microcontroller

DS97LVO0701 2-27

1

CTR1 Register Description

Mode. If it is 0, the Counter/Timers are in the transmit

mode, otherwise they are in the demodulation mode.
P36_Out/Demodulator_Input. In Transmit Mode, this bit

defines whether P36 is used as a normal output pin or the
combined output of T8 and T16.

In Demodulation Mode, this bit defines whether the input
signal to the Counter/Timers is from P20 or P31.

T8/T16_Logic/Edge _Detect. In Transmit Mode, this field
defines how the outputs of T8 and T16 are combined
(AND, OR, NOR, NAND).

In Demodulation Mode, this field defines which edge
should be detected by the edge detector.

Transmit_Submode/Glitch Filter. In Transmit Mode, this
field defines whether T8 and T16 are in the "Ping-Pong"
mode or in independent normal operation mode. Setting
this field to "Normal Operation Mode" terminates the "Ping­Pong Mode" operation. When set to 10, T16 is immediately
forced to a 0.

In Demodulation Mode, this field defines the width of the
glitch that should be filtered out.

Initial_T8_Out/Rising_Edge. In Transmit Mode, if 0, the
output of T8 is set to 0 when it starts to count. If 1, the out­put of T8 is set to 1 when it starts to count. When this bit is
set to 1 or 0, T8_OUT will be set to the opposite state of
this bit. This insures that when the clock is enabled a tran­sition occurs to the initial state set by CTR1, D1.

In Demodulation Mode, this bit is set to 1 when a rising
edge is detected in the input signal. In order to reset it, a 1
should be written to this location.

Initial_T16 Out/Falling _Edge. In Transmit Mode, if it is 0,
the output of T16 is set to 0 when it starts to count. If it is
1, the output of T16 is set to 1 when it starts to count. This
bit is effective only in Normal or Ping-Pong Mode (CTR1,
D3, D2). When this bit is set, T16_OUT will be set to the
opposite state of this bit. This insures that when the clock
is enabled a transition occurs to the initial state set by
CTR1, D0.

In Demodulation Mode, this bit is set to 1 when a falling
edge is detected in the input signal. In order to reset it, a 1
should be written to this location.

Note: Modifying CTR1, (D1 or D0) while counters are en­abled will cause un-predictable output from T8/16_out.

Z86L78
IR/Low-Voltage Microcontroller Zilog

2-28 DS97LVO0701

CTR2 (D)%02: Counter/Timer16 Control Register.

Field Bit Position Value Description

T16_Enable 7------- R

W

0*

1
0
1

Counter Disabled
Counter Enabled
Stop Counter
Enable Counter

Single/Modulo-N -6------ R/W

0
1

0
1

Transmit Mode
Modulo-N
Single Pass
Demodulation Mode
T16 Recognizes Edge
T16 Does Not Recognize Edge

Time_Out --5----- R

W

0
1
0
1

No Counter Time-Out
Counter Time-Out Occurred
No Effect
Reset Flag to 0

T16 _Clock ---43--- R/W 00

01
10
11

SCLK
SCLK/2
SCLK/4
SCLK/8

Capture_INT_Mask -----2-- R/W 0

1

Disable Data Capture Int.
Enable Data Capture Int.

Counter_INT_Mask ------1- R/W 0 Disable Time-Out Int.

Enable Time-Out Int.

P35_Out -------0 R/W 0 P35 as Port Output*

T16 Output on P35

Note: * Indicates the value upon Power-On Reset.

Z86L78

Zilog IR/Low-Voltage Microcontroller

DS97LVO0701 2-29

1

CTR2 Description

T16_Enable. This field enables T16 when set to 1.
Single/Modulo-N. In Transmit Mode, when set to 0, the

counter reloads the initial value when terminal count is
reached. When set to 1, the counter stops when the termi­nal count is reached.

In Demodulation Mode, when set to 0 , T16 captures and
reloads on detection of all the edges; when set to 1, T16
captures and detects on the first edge, but ignores the sub­sequent edges. For details, see the description of T16 De­modulation Mode.

Time_Out. This bit is set when T16 times out (terminal
count reached). In order to reset it, a 1 should be written to
this location.

T16_Clock. Defines the frequency of the input signal to
Counter/Timer16.

Capture_INT_Mask. Set this bit to allow interrupt when
data is captured into LO16 and HI16.

Counter_INT_Mask. Set this bit to allow interrupt when
T16 times out.

P35_Out. This bit defines whether P35 is used as a normal
output pin or T16 output.

Port pins configured as outputs are ignored as an SMR2
recover source. For example, if NAND of P23-P20 is se­lected as the recover source and P20 is configured as out­put, then P20 is ignored as a recover source. The effective
recover source in this case is NAND of P23-P21.

SMR2(F)%0D: Stop-Mode Recovery Register 2.

Field Bit Position Value Description

Reserved 7------- 0 Reserved (Must be 0)
Recovery Level -6------ W0*

1

Low

High
Reserved --5----- 0 Reserved (Must be 0)
Source ---432-- W 000*

001
010
011
100
101
110
111

A. POR Only

B. NAND of P23-P20

C. NAND of P27-P20

D. NOR of P33-P31

E. NAND of P33-P31

F. NOR of P33-P31, P00,P07

G. NAND of P33-P31,P00,P07

H. NAND of P33-P31,P22-P20
Reserved ------10 00 Reserved (Must be 0)

Note: * Indicates the value upon Power-On Reset.

Z86L78
IR/Low-Voltage Microcontroller Zilog

2-30 DS97LVO0701

Counter/Timer Functional Blocks

Figure 18. Glitch Filter Circuitry

Glitch

Filter

Edge

Detector

CTR1 D5,D4

CTR1 D3,D2

Pos Edge
Neg Edge

MUX

CTR1 D6

P31

P20

Figure 19. 8-Bit Counter/Timer Circuit

Z8 Data Bus

Pos Edge
Neg Edge

CTR0 D2

IRQ4

CTR0 D1

T8_OUT P34

TC8LTC8H

Clock

Select

SCLK

CTR0 D4, D3

Clock

8-Bit

Counter T8

HI8

LO8

Z8 Data Bus

Z86L78

Zilog IR/Low-Voltage Microcontroller

DS97LVO0701 2-31

1

Input Circuit

The edge detector monitors the input signal on P31 or P20.
Based on CTR1 D5-D4, a pulse is generated at the Pos
Edge or Neg Edge line when an edge is detected. Glitches
in the input signal which have a width less than specified
(CTR1 D3, D2) are filtered out.

T8 Transmit Mode

When T8 is enabled, the output of T8 depends on CTR1,
D1. If it is 0, T8_OUT is 1. If it is 1, T8_OUT is 0.

When T8 is enabled, the output T8_OUT switches to the
initial value (CTR1 D1). If the initial value (CTR1 D1) is 0,
TC8L is loaded, otherwise TC8H is loaded into the
counter. In Single-Pass Mode (CTR0 D6), T8 counts down
to 0 and stops, T8_OUT toggles, the time-out status bit
(CTR0 D5) is set, and a time-out interrupt can be generat­ed if it is enabled (CTR0 D1) (Figure 18). In Modulo-N
Mode, upon reaching terminal count, T8_OUT is toggled,
but no interrupt is generated. Then T8 loads a new count
(if the T8_OUT level now is 0), TC8L is loaded; if it is 1,
TC8H is loaded. T8 counts down to 0, toggles T8_OUT,

sets the time-out status bit (CTR0 D5) and generates an
interrupt if enabled (CTR0 D1) (Figure 19). This completes
one cycle. T8 then loads from TC8H or TC8L according to
the T8_OUT level, and repeats the cycle.

The user can modify the values in TC8H or TC8L at any
time. The new values take effect when they are loaded.
Care must be taken not to write these registers at the time
the values are to be loaded into the counter/timer, to en­sure known operation. An initial count of 1 is not al-
lowed (a non-function will occur). An initial count of 0
will cause TC8 to count from 0 to %FF to %FE (Note, % is
used for hexadecimal values). Transition from 0 to %FF is
not a time-out condition.

Note: Using the same instructions for stopping the
counter/timers and setting the status bits is not rec­ommended. Two successive commands, first stopping

the counter/timers, then resetting the status bits is neces­sary. This is required because it takes one counter/timer
clock interval for the initiated event to actually occur.

Figure 20. T8_OUT in SIngle-Pass Mode

TC8H Counts

“Counter Enable” Command,

T8_OUT Switches To Its

Initial Value (CTR1 D1)

T8_OUT Toggles,

Time-Out Interrupt

Figure 21. T8_OUT in Modulo-N Mode

“Counter Enable” Command,

T8_OUT Switches To Its

Initial Value (CTR1 D1)

T8_OUT Toggles

T8_OUT TC8L TC8H TC8L TC8H TC8L

Time-Out Interrupt

Time-Out Interrupt

Z86L78
IR/Low-Voltage Microcontroller Zilog

2-32 DS97LVO0701

FUNCTIONAL DESCRIPTION (Continued)

T8 Demodulation Mode

The user should program TC8L and TC8H to %FF. After
T8 is enabled, when the first edge (rising, falling, or both
depending on CTR1 D5, D4) is detected, it starts to count
down. When a subsequent edge (rising, falling, or both de­pending on CTR1 D5, D4) is detected during counting, the
current value of T8 is one's complemented and put into
one of the capture registers. If it is a positive edge, data is

put into LO8, if negative edge, HI8. One of the edge detect
status bits (CTR1 D1, D0) is set, and an interrupt can be
generated if enabled (CTR0 D2). Meanwhile, T8 is loaded
with %FF and starts counting again. Should T8 reach 0,
the time-out status bit (CTR0 D5) is set, an interrupt can be
generated if enabled (CTR0 D1), and T8 continues count­ing from %FF (Figure 23).

Figure 22. Demodulation Mode Count Capture Flowchart

T8 (8-Bit)

Count Capture

T8_Enable

(Set By User)

No

Yes

Edge Present

No

Yes

What Kind Of Edge

Pos

T8 → L08

Neg

T8 → HI8

%FF → T8

Z86L78

Zilog IR/Low-Voltage Microcontroller

DS97LVO0701 2-33

1

Figure 23. Transmit Mode Flowchart

T8 (8-Bit)

Transmit Mode

T8_Enable Bit Set

CTR0, D7

No

Yes

CTR1, D1 Value

0

Load TC8L

Reset T8_OUT

Load TC8H

Set T8_OUT

Reset T8_Enable Bit

Set Time-out Status Bit

(CTR0 D5) and Generate

Timeout_Int If Enabled

No

T8_Timeout

Modulo-N

T8_OUT Value

Load TC8L

Reset T8_OUT

Load TC8H

Set T8_OUT

Start T8

No

T8_Timeout

Stop T8

Yes

Set Time-out Status Bit

(CTR0 D5) and Generate

Timeout_Int If Enabled

Single Pass

1

10

T8_OUT

Toggle

Start T8

Single Pass?

Start T8

Z86L78
IR/Low-Voltage Microcontroller Zilog

2-34 DS97LVO0701

FUNCTIONAL DESCRIPTION (Continued)

T16 Transmit Mode

In Normal or Ping-Pong Mode, the output of T16 when not
enabled is dependent on CTR1, D0. If it is a 0, T16_OUT
is a 1; if it is a 1, T16_OUT is 0. The user can force the out­put of T16 to either a 0 or 1 whether it is enabled or not by
programming CTR1 D3, D2 to a 10 or 11.

When T16 is enabled, TC16H * 256 + TC16L is loaded,
and T16_OUT is switched to its initial value (CTR1 D0).
When T16 counts down to 0, T16_OUT is toggled (in Nor­mal or Ping-Pong Mode), an interrupt is generated if en­abled (CTR2 D1), and a status bit (CTR2 D5) is set. Note
that global interrupts will override this function as de­scribed in the interrupts section. If T16 is in Single-Pass
Mode, it is stopped at this point. If it is in Modulo-N Mode,
it is loaded with TC16H * 256 + TC16L and the counting
continues.

The user can modify the values in TC16H and TC16L at
any time. The new values take effect when they are load­ed. Care must be taken not to load these registers at the
time the values are to be loaded into the counter/timer, to
ensure known operation. An initial count of 1 is not al­lowed. An initial count of 0 will cause T16 to count from 0
to %FFFF to %FFFE. Transition from 0 to %FFFF is not a
time-out condition.

Figure 24. 16-Bit Counter/Timer Circuits

Z8 Data Bus

Pos Edge
Neg Edge

CTR2 D2

IRQ3

CTR2 D1

T16_OUT
(P35)

TC16LTC16H

Clock

Select

SCLK

CTR2 D4, D3

Clock

16-Bit

Counter

T16

HI16

LO16

Z8 Data Bus

Z86L78

Zilog IR/Low-Voltage Microcontroller

DS97LVO0701 2-35

1

T16 Demodulation Mode

The user should program TC16L and TC16H to %FF. After
T16 is enabled, when the first edge (rising, falling, or both
depending on CTR1 D5, D4) is detected, T16 captures
HI16 and LO16, reloads and begins counting.

If D6 of CTR2 is 0: When a subsequent edge (rising, fall­ing, or both depending on CTR1 D5, D4) is detected during
counting, the current count in T16 is one's complemented
and put into HI16 and LO16. When data is captured, one
of the edge detect status bits (CTR1 D1, D0) is set and an
interrupt is generated if enabled (CTR2 D2). T16 is loaded
with %FFFF and starts again.

If D6 of CTR2 is 1: T16 ignores the subsequent edges in
the input signal and continues counting down. A time out
of T8 will cause T16 to capture its current value and gen­erate an interrupt if enabled (CTR2, D2). In this case, T16
does not reload and continues counting. If D6 bit of CTR2
is toggled (by writing a 0 then a 1 to it), T16 will capture and
reload on the next edge (rising, falling, or both depending
on CTR1 D5, D4) but continue to ignore subsequent edg­es.

Should T16 reach 0, it continues counting from %FFFF;
meanwhile, a status bit (CTR2 D5) is set and an interrupt
time-out can be generated if enabled (CTR2 D1).

Figure 25. T16_OUT in Single-Pass Mode

TC16H*256+TC16L Counts

“Counter Enable” Command,

T16_OUT Switches To Its

Initial Value (CTR1 D0)

T16_OUT Toggles,

Time-Out Interrupt

Figure 26. T16_OUT in Modulo-N Mode

TC16H*256+TC16L

“Counter Enable” Command,

T16_OUT Switches To Its

Initial Value (CTR1 D0)

T16_OUT Toggles,

Time-Out Interrupt

TC16H*256+TC16L

TC16H*256+TC16L

T16_OUT Toggles,
Time-Out Interrupt

T16_OUT

Z86L78
IR/Low-Voltage Microcontroller Zilog

2-36 DS97LVO0701

FUNCTIONAL DESCRIPTION (Continued)

Ping-Pong Mode

This operation mode is only valid in Transmit Mode. T8
and T16 need to be programmed in Single-Pass Mode
(CTR0 D6, CTR2 D6) and Ping-Pong Mode needs to be
programmed in CTR1 D3, D2. The user can begin the op­eration by enabling either T8 or T16 (CTR0 D7 or CTR2
D7). For example, if T8 is enabled, T8_OUT is set to this
initial value (CTR1 D1). According to T8_OUT's level,
TC8H or TC8L is loaded into T8. After the terminal count
is reached, T8 is disabled and T16 is enabled. T16_OUT
switches to its initial value (CTR1 D0), data from TC16H
and TC16L is loaded, and T16 starts to count. After T16

reaches the terminal count it stops, T8 is enabled again,
and the whole cycle repeats. Interrupts can be allowed
when T8 or T16 reaches terminal control (CTR0 D1, CTR2
D1). To stop the Ping-Pong operation, write 00 to bits D3
and D2 of CTR1.

Note: Enabling Ping-Pong operation while the
counter/timers are running may cause intermittent
counter/timer function. Therefore, disable the

counter/timers, then reset the status flags prior to institut­ing this operation.

To Initiate Ping-Pong Mode

First, make sure both counter/timers are not running. Then
set T8 into Single-Pass Mode (CTR0 D6), set T16 into Sin­gle-Pass Mode (CTR2 D6), and set Ping-Pong Mode
(CTR1 D2, D3). These instructions do not have to be in
any particular order. Finally, start Ping-Pong Mode by en­abling either T8 (CTR0 D7) or T16 (CTR2 D7).

During Ping-Pong Mode

The enable bits of T8 and T16 (CTR0 D7, CTR2 D7) will
be cleared by hardware. The time-out bits (CTR0 D5,
CTR2 D5) will be set every time the counter/timers reach
the terminal count.

Figure 27. Ping-Pong Mode

Enable

TC8

Time-Out

Enable

TC16

Time-Out

Ping-Pong

CTR1 D3,D2

Z86L78

Zilog IR/Low-Voltage Microcontroller

DS97LVO0701 2-37

1

Figure 28. T8_OUT and T16_OUT in Ping-Pong Mode

TC8H

Enable T8,

T8_OUT Switches

To Its Initial Value

TC16H*256+TC16L

T16_OUT Toggles

T8_OUT

TC8H

TC16H*256+TC16L

T16_OUT

T16_OUT

T16_OUT Switches To Its Initial
Value When TC16 Is Enabled

T8_OUT Toggles

T8_OUT Toggles

Figure 29. Output Circuit

AND/OR/NOR/NAND

Logic

T8_OUT

CTR1 D5,D4

P34_INTERNAL

CTR0 D0

P36_INTERNAL

CTR1 D6

P35_INTERNAL

CTR2 D0

P35_EXT

P36_EXT

P34_EXT

MUX

MUX

MUX

T16_OUT

MUX

CTR1, D2

CTR1 D3

Z86L78
IR/Low-Voltage Microcontroller Zilog

2-38 DS97LVO0701

FUNCTIONAL DESCRIPTION (Continued)

Interrupts. The Z86L78 has five different interrupts, which

are maskable and prioritized (Figure 30). The five sources
are divided as follows: two are claimed by Port 3 lines P33,
P31, one by the low voltage detect circuit (IRQ0) and the

remaining two by the counter/timers (Table 5). The Inter­rupt Mask Register globally or individually enables or dis­ables the five interrupt requests.

Figure 30. Interrupt Block Diagram

Interrupt

Edge

Select

IRQ Register (D6, D7)

IRQ

IMR

IPR

Priority

Logic

5

Vector Select

IRQ0

IRQ2

Global

Interrupt

Enable

Interrupt
Request

IRQ

1 3 4

Z86L78

Zilog IR/Low-Voltage Microcontroller

DS97LVO0701 2-39

1

When more than one interrupt is pending, priorities are re­solved by a programmable priority encoder controlled by
the Interrupt Priority register. An interrupt machine cycle is
activated when an interrupt request is granted. This dis­ables all subsequent interrupts, saves the Program
Counter and Status Flags, and then branches to the pro­gram memory vector location reserved for that interrupt.
All Z86L78 interrupts are vectored through locations in the
program memory. This memory location and the next byte
contain the 16-bit address of the interrupt service routine
for that particular interrupt request. To accommodate
polled interrupt systems, interrupt inputs are masked and
the Interrupt Request register is polled to determine which
of the interrupt requests need service.

An interrupt resulting from AN1 is mapped into IRQ2, and
an interrupt from AN2 is mapped into IRQ0. Interrupts
IRQ2 and IRQ0 may be rising, falling, or both edge trig­gered, and are programmable by the user. The software
can poll to identify the state of the pin.

Programming bits for the Interrupt Edge Select are located
in the IRQ Register (R250), bits D7 and D6. The configu­ration is shown in Table 4.

Notes: In analog mode, the Stop-Mode Recovery sources
selected by the SMR register are connected to the IRQ1
input. Any of the Stop-Mode Recovery sources for SMR
(except P31,P32 and P33) can be used to generate IRQ1
(falling edge triggered).

Table 3. Interrupt Types, Sources and Vectors

Name Source

Vector

Location Comments

IRQ0 IRQ0 0, 1 External (P32),

Rising Falling Edge
Triggered

IRQ1, IRQ1 2, 3 External (P33),

Falling Edge
Triggered

IRQ2 /DAV2,

IRQ2, T

IN

4, 5 External (P31),

Rising Falling Edge

Triggered
IRQ3 T16 6, 7 Internal
IRQ4 T8 8, 9 Internal

Table 4. Interrupt Types, Sources, and Vectors

IRQ Interrupt Edge

D7 D6 IRQ2(P31) IRQ0 (P32)

00 F F
01 F R
10 R F
1 1 R/F R/F

Notes:

F = Falling Edge
R = Rising Edge

Z86L78
IR/Low-Voltage Microcontroller Zilog

2-40 DS97LVO0701

FUNCTIONAL DESCRIPTION (Continued)

Clock. The Z86L78 on-chip oscillator has a high-gain, par-

allel-resonant amplifier for connection to a crystal, LC, ce­ramic resonator, or any suitable external clock source
(XTAL1 = Input, XTAL2 = Output). The crystal should be
AT cut, 1 MHz to 8 MHz maximum, with a series resistance
(RS) less than or equal to 100 Ohms. The Z86L7X on-chip
oscillator may be driven with a cost-effective RC network
or other suitable external clock source. For 32 kHz crystal
operation a mask option is selected which disables the in­ternal XTAL1/2 feedback resistor. The external compo­nents for using a 32 kHz crystal include a feedback (Rf)
and serial (Rd) resistor as shown in Figure 33.

The crystal should be connected across XTAL1 and
XTAL2 using the recommended capacitors (capacitance
greater than or equal to 22 pF) from each pin to ground.
The RC oscillator configuration is an external resistor con­nected from XTAL1 to XTAL2, with a frequency-setting ca­pacitor from XTAL1 to ground (Figure 32).

Power-On Reset (POR). A timer circuit clocked by a ded­icated on-board RC oscillator is used for the Power-On Re­set (POR) timer function. The POR time allows VCC and
the oscillator circuit to stabilize before instruction execu­tion begins.

The POR timer circuit is a one-shot timer triggered by one
of three conditions:

1. Power Fail to Power OK status.

2. Stop-Mode Recovery (if D5 of SMR = 1).

3. WDT Time-Out.
The POR time is a nominal 5 ms. Bit 5 of the Stop-Mode

Register determines whether the POR timer is bypassed
after Stop-Mode Recovery (typical for external clock, RC,
LC oscillators).

Figure 31. Oscillator Configuration

XTAL1

XTAL2

C1

C2

C1

C2

C1

XTAL1

XTAL2

XTAL1

XTAL2

XTAL1

XTAL2

Ceramic Resonator or Crystal

C1, C2 = 47 pF TYP *
f = 8 MHz

LC

C1, C2 = 22 pF
L = 130 µH *

f = 3 MHz *

RC

@ 3V VCC (TYP)
C1 = 33 pF *

R = 1K *

External Clock

L

R

* Preliminary value including pin parasitics

C1

32 kHz XTAL
C1 = 20 pF, C = 33
pF
Rd = 56 - 470K
Rf =10 M

Rf

C2 Rd

XTAL1

XTAL2

Z86L78

Zilog IR/Low-Voltage Microcontroller

DS97LVO0701 2-41

1

HALT. HALT turns off the internal CPU clock, but not the

XTAL oscillation. The counter/timers and external inter­rupts IRQ0, IRQ1, IRQ2, IRQ3, and IRQ4 remain active.
The devices are recovered by interrupts, either externally
or internally generated. An interrupt request must be exe­cuted (enabled) to exit HALT Mode. After the interrupt ser­vice routine, the program continues from the instruction af­ter the HALT.

STOP. This instruction turns off the internal clock and ex­ternal crystal oscillation and reduces the standby current
to 10 µA (typical) or less. STOP Mode is terminated only
by a reset, such as WDT time-out, POR, SMR, or external
reset. This causes the processor to restart the application
program at address 000CH.

In order to enter STOP (or HALT) Mode, it is necessary to
first flush the instruction pipeline to avoid suspending exe­cution in mid-instruction. To do this, the user must execute
a NOP (opcode = FFH) immediately before the appropriate
SLEEP instruction, i.e.,

FF NOP ; clear the pipeline
6F STOP ; enter STOP Mode

or
FF NOP ; clear the pipeline
7F HALT ; enter HALT Mode

Port Configuration Register (PCON). The PCON regis­ter configures the comparator output on Port 3. It is locat­ed in the expanded register file at Bank F, location 00 (Fig­ure 32).

Comparator Output Port 3 (D0). Bit 0 controls the com­parator used in Port 3. A 1 in this location brings the com­parator outputs to P34 and P37, and a 0 releases the Port
to its standard I/O configuration.

Figure 32. Port Configuration Register (PCON)

(Write Only)

Reserved (Must be 1)

D7 D6 D5D4D3 D2 D1 D0

PCON (FH) 00H

Comparator Output Port 3
0 P34, P37 Standard Output*
1 P34, P37 Comparator Output

* Default Setting After Reset

Z86L78
IR/Low-Voltage Microcontroller Zilog

2-42 DS97LVO0701

FUNCTIONAL DESCRIPTION (Continued)

Stop-Mode Recovery Register (SMR). This register se-

lects the clock divide value and determines the mode of
Stop-Mode Recovery (Figure 33). All bits are Write Only
except bit 7, which is Read Only. Bit 7 is a flag bit that is
hardware set on the condition of STOP recovery and reset

by a power-on cycle. Bit 6 controls whether a low level or
a high level is required from the recovery source. Bit 5 con­trols the reset delay after recovery. Bits D2, D3, and D4, of
the Stop-Mode Recovery signal. Bits D0 determines if
SCLK/TCLK are divided by 16 or not.

Figure 33. Stop-Mode Recovery Register

D7 D6 D5 D4 D3 D2 D1 D0

SMR (0F) 0B

SCLK/TCLK Divide-by-16
0 OFF
1 ON

Reserved (Must be 0)
Stop-Mode Recovery Source

000
001
010
011
100
101
110
111

Stop Delay
0 OFF
1 ON

Stop Recovery Level
0 Low
1 High

Stop Flag
0 POR
1 Stop Recovery**

* Default Setting After Reset
** Default Setting After Reset and Stop-Mode Recovery

**

*

*

*

*

POR Only
Reserved
P31
P32
P33
P27
P2 NOR 0-3
P2 NOR 0-7

Z86L78

Zilog IR/Low-Voltage Microcontroller

DS97LVO0701 2-43

1

SCLK/TCLK Divide-by-16 Select (D0). D0 of the SMR

controls a Divide-by-16 prescaler of SCLK/TCLK (Figure

34). The purpose of this control is to selectively reduce de­vice power consumption during normal processor execu­tion (SCLK control) and/or HALT Mode (where TCLK
sources interrupt logic). After Stop-Mode Recovery, this bit
is set to a 0.

STOP-Mode Recovery Source (D2, D3, and D4). These
three bits of the SMR specify the wake up source of the
STOP recovery (Figure 35 and Table 5).

Note: Any Port 2 bit defined as an output will drive the cor­responding input to the default state to allow the remaining
inputs to control the AND/OR function. Refer to SMR2 reg­ister for other recover sources.

STOP-Mode Recovery Delay Select (D5). This bit, if
Low, disables the 5 ms /RESET delay after Stop-Mode Re­covery. The default configuration of this bit is one. If the
"fast" wake up is selected, the Stop-Mode Recovery
source needs to be kept active for at least 5TpC.

STOP-Mode Recovery Edge Select (D6). A 1 in this bit
position indicates that a High level on any one of the recov­ery sources wakes the Z86L78 from STOP Mode. A 0 in­dicates Low level recovery. The default is 0 on POR (Fig­ure 35).

Cold or Warm Start (D7). This bit is set by the device
upon entering STOP Mode. It is a Read Only Flag bit. A 1
in D7 (warm) indicates that the device will awaken from a
SMR source or a WDT while in STOP Mode. A 0 in this bit
(cold) indicates that the device will be rest by a POR, WDT
while not in STOP, or the device awakened from a low volt­age standby mode.

Stop-Mode Recovery Register 2 (SMR2). This register
determines the mode of stop mode recovery for SMR2
(Figure 36).

If SMR2 is used in conjunction with SMR, either of the
specified events will cause a Stop-Mode Recovery.

Note: Port pins configured as outputs are ignored as a
SMR or SMR2 recovery source. For example, if the NAND
of P23-20 is selected as the recovery source and P20 is
configured as an output then the remaining SMR pins
(P23-P21) form the NAND equation.

Figure 34. SCLK Circuit

Table 5. STOP-Mode Recovery Source

SMR: 432

Operation

Description of ActionD4 D3 D2

0 0 0 POR and/or external reset

recovery
0 0 1 Reserved
0 1 0 P31 transition
0 1 1 P32 transition
1 0 0 P33 transition
1 0 1 P27 transition
1 1 0 Logical NOR of P20 through

P23
1 1 1 Logical NOR of P20 through

P27

SMR, D0

÷

2

÷

16

OSC

SCLK
TCLK

Z86L78
IR/Low-Voltage Microcontroller Zilog

2-44 DS97LVO0701

FUNCTIONAL DESCRIPTION (Continued)

Figure 35. Stop-Mode Recovery Register 2

((0F) DH: D2-D4, D6 Write Only

D7 D6 D5 D4 D3 D2 D1 D0

SMR2 (0F) 0DH

Reserved (Must be 0)
Reserved (Must be 0)

Stop-Mode Recovery Source 2
000 POR only*
001 NAND P20, P21, P22, P23
010 NAND P20, P21, P22, P23, P24, P25, P26, P27
011 NOR P31, P32, P33
100 NAND P31, P32, P33
101 NOR P31, P32, P33, P00, P07
110 NAND P31, P32, P33, P00, P07
111 NAND P31, P32, P33, P20, P21, P22

Reserved
(Must be 0)

Recovery Level
0 Low*
1 High

Reserved (Must be 0)

Note: If used in conjunction with SMR,
either of the two specified events will
cause a Stop-Mode Recovery.

*Default Setting After Reset

Z86L78

Zilog IR/Low-Voltage Microcontroller

DS97LVO0701 2-45

1

Figure 36. Stop-Mode Recovery Source

P00

P32

VCC

P31

P32

P33

P27

P20
P23

P20
P27

SMR D40D30D2

0

SMR D40D31D2

0

SMR D40D31D2

1

SMR D41D30D2

0

SMR D41D30D2

1

SMR D41D31D2

0

SMR D41D31D2

1

SMR2 D40D30D2

0

SMR2 D40D31D2

0

SMR2 D40D31D2

1

SMR2 D41D30D2

0

SMR2 D41D30D2

1

SMR2 D41D31D2

0

SMR2 D41D31D2

1

SMR2 D40D30D2

1

VCC

P20

P32

P23

P20
P27

P31
P33

P31
P33

P32

P31
P33

P00
P07

P32

P31
P33
P07

P20

P32

P31
P33
P21

P22

SMR2 D6

SMR D6

To RESET and WDT
Circuitry (Active Low)

S1

S2

S3

S4

To IRQ1

Z86L78
IR/Low-Voltage Microcontroller Zilog

2-46 DS97LVO0701

FUNCTIONAL DESCRIPTION (Continued)

Watch-Dog Timer Mode Register (WDTMR). The WDT

is a retriggerable one-shot timer that resets the Z8 if it
reaches its terminal count. The WDT must initially be en­abled by executing the WDT instruction and refreshed on
subsequent executions of the WDT instruction. The WDT
circuit is driven by an on-board RC oscillator or external
oscillator from the XTAL1 pin. The WDT instruction affects
the Zero (Z), Sign (S), and Overflow (V) flags.

The POR clock source is selected with bit 4 of the WDT
register. Bit 0 and 1 control a tap circuit that determines the
time-out period. Bit 2 determines whether the WDT is ac­tive during HALT and Bit 3 determines WDT activity during
STOP. Bits 5 through 7 are reserved (Figure 38). This reg­ister is accessible only during the first 64 processor cycles
(128 XTAL clocks) from the execution of the first instruc­tion after Power-On-Reset, Watch-Dog Reset, or a Stop­Mode Recovery (Figure 35). After this point, the register
cannot be modified by any means, intentional or other­wise. The WDTMR cannot be read and is located in Bank
F of the Expanded Register Group at address location
0FH. It is organized as follows:

Figure 37. Watch-Dog TImer Mode Register

(Write Only)

D7 D6 D5 D4 D3 D2 D1 D0

WDTMR (0F) F

WDT TAP INT RC OSC External Clock
00 5 ms 256 TpC
01 10 ms 512 TpC
10 20 ms 1024 TpC
11 80 ms 4096 TpC

WDT During HALT
0 OFF
1 ON

WDT During STOP
0 OFF
1 ON

XTAL1/INT RC Select for WDT
0 On-Board RC
1 XTAL

Reserved (Must be 0)

* Default Setting After Reset

*

*

*

*

Z86L78

Zilog IR/Low-Voltage Microcontroller

DS97LVO0701 2-47

1

WDT Time Select (D0, D1). Selects the WDT time period.

It is configured as shown in Table 6.

WDTMR During HALT (D2). This bit determines whether
or not the WDT is active during HALT Mode. A 1 indicates
active during HALT. The default is 1.

WDTMR During STOP (D3). This bit determines whether
or not the WDT is active during STOP Mode. Since the
XTAL clock is stopped during STOP Mode, the on-board
RC has to be selected as the clock source to the
WDT/POR counter. A 1 indicates active during STOP. The
default is 1.

Clock Source for WDT (D4). This bit determines which
oscillator source is used to clock the internal POR and
WDT counter chain. If the bit is a 1, the internal RC oscil­lator is bypassed and the POR and WDT clock source is
driven from the external pin, XTAL1. The default configu­ration of this bit is 0, which selects the RC oscillator.

Table 6. WDT TIme Select

D1 D0

Time-Out of

Internal RC

OSC

Time-Out of

XTAL Clock

0 0 5 ms min 256 TpC
0 1 10 ms min 512 TpC
1 0 20 ms min 1024 TpC
1 1 80 ms min 4096 TpC

Notes:

TpC = XTAL clock cycle
The default on reset is 10 ms

Figure 38. Resets and WDT

CLK

18 Clock RESET

Generator

RESET

* CLR 2

WDT TAP SELECT

INTERNAL

RC

OSC.

CLK

*CLR1

POR

WDT1

234

Low Operating
Voltage Det.

Internal
RESET
Active
High

CK Source

Select

(WDTMR)

XTAL

VDD

VBO/VLV
2V REF.

From Stop

Mode

Recovery

Source

WDT

Stop Delay

Select (SMR)

12 ns Glitch Filter

+

-

5 Clock

Filter

WDT/POR Counter Chain

M
U

X

/RESET

* /CLR1 and /CLR2 enable the WDT/POR and
18 Clock Reset timers upon a Low to High input translation.

Z86L78
IR/Low-Voltage Microcontroller Zilog

2-48 DS97LVO0701

FUNCTIONAL DESCRIPTION (Continued)

Reset Functional Operation. Reset is internally driven

by four sources:

1. POR. (0 volts to operating voltage condition) usually
occurs upon powering up the MCU.

2. WDT. The WDT counts down and generates a reset,
usually to "wake" the part from a "sleep" condition.

3. Low Voltage Detection/Standby. An on-chip Voltage
Comparator checks that the VCC is at the required
level for correct operation of the device. Reset is
globally driven when VCC falls below VLV (Vrf1). A
small further drop in VCC causes the XTAL1 and
XTAL2 circuitry to stop the crystal or resonator clock.
Typical power consumption in this Low Voltage
Standby mode (I

LV

) is about 45 µA (varying with the
number of Masks selectable options enabled). When
the power level is returned to above VLV, the device
will perform a POR and function normally. If the VCC is
allowed to stay above 1.5V, the RAM content is
preserved. Low Voltage Standby was designed to
allow the device to draw power from board level
decoupling capacitors during battery changes.

4. Stop Mode Recovery (Partial reset).
Low Voltage Protection. An on-board Voltage Compara-

tor checks that V

CC

is at the required level to ensure cor-

rect operation of the device. Reset is globally driven if V

CC

is below Vrf1.
Maximum (Vrf1) Conditions:
TA = 0°C, +70°C Internal clock frequency equal to or less

than 4.0 MHz

Note: The internal clock frequency is one-half the external
clock frequency.

The device functions normally at or above Vrf1 under all
conditions (Figure 39).

Mask Selectable Options. There are five Mask Select­able Options to choose from based on ROM code require­ments. These are:

RC/Other Clock Source

Port 0 Pull-ups On/Off
Port 2 Pull-ups On/Off
Port 3 Pull-ups On/Off

32 kHz Option On/Off

Figure 39. Z86L78 Low Voltage

vs Temperature at 8 MHz

0

15

25

35

45

55

Temperature

70°C

Vrf1

T
B
D

Z86L78

Zilog IR/Low-Voltage Microcontroller

DS97LVO0701 2-49

1

EXPANDED REGISTER FILE CONTROL REGISTERS (0D)

Figure 40. TC8 Control Register

((0D) 0H: Read/Write Accept Where Noted)

D7 D6 D5 D4 D3 D2 D1 D0

CTR0 (0D) 0H

0 P34 as Port Output*
1 Timer8 Output

0 Disable T8 Time Out Interrupt
1 Enable T8 Time Out Interrupt

0 Disable T8 Data Capture Interrupt
1 Enable T8 Data Capture Interrupt

00 SCLK on T8
01 SCLK/2 on T8
10 SCLK/4 on T8
11 SCLK/8 on T8

R 0 No T8 Counter Time Out
R 1 T8 Counter Time Out Occured
W 0 No Effect
W 1 Reset Flag to 0

* Default Setting After Reset

0 Modulo-N
1 Single Pass

R 0 T8 Disabled *
R 1 T8 Enabled
W 0 Stop T8
W 1 Enable T8

Z86L78
IR/Low-Voltage Microcontroller Zilog

2-50 DS97LVO0701

Figure 41. T8 and T16 Common Control Functions

((0D) 1H: Read/Write)

D7 D6 D5 D4 D3 D2 D1 D0

CTR1 (0D) 1H

0 T16_OUT is 0 Initially
1 T16_OUT is 1 Initially

R/W

R
R

W
W

0 No Falling Edge Detection
1 Falling Edge Detection

0 No Effect
1 Reset Flag to 0

0 T8_OUT is 0 Initially
1 T8_OUT is 1 Initially

0 No Rising Edge Detection
1 Rising Edge Detection

0 0 Normal Operation
0 1 Ping-Pong Mode
1 0 T16_OUT = 0
1 1 T16_OUT = 1

Transmit Mode/T8/T16 Logic

0 0 Falling Edge Detection
0 1 Rising Edge Detection
1 0 Both Edge Detection
1 1 Reserved

0 P36 as Port Output*
1 P36 as T8/T16_OUT

0 Transmit Mode*
1 Demodulation Mode

0 0 No Filter
0 1 4 SCLK Cycle Filter
1 0 8 SCLK Cycle Filter
1 1 16 SCLK Cycle Filter

Demodulation Mode

Transmit Mode

Transmit Mode
R/W

Demodulation Mode
R

R
W

W
Transmit Mode

Demodulation Mode

0 0 AND
0 1 OR
1 0 NOR
1 1 NAND

Demodulation Mode

Transmit Mode

0 P31 as Demodulator Input
1 P20 as Demodulator Input

Demodulation Mode

Transmit/Demodulation Modes

0 No Effect
1 Reset Flag to 0

Note: Care must be taken in differentiating
Transmit Mode from Demodulation Mode.
Depending on which of these two modes is
operating, the CTR1 bit will have different
functions.

*Note: Changing from one mode to
another cannot be
done without disabling the
counter/timers.

Z86L78

Zilog IR/Low-Voltage Microcontroller

DS97LVO0701 2-51

1

Figure 42. T16 Control Register

((0D) Read/Write Except Where Noted

D7 D6 D5 D4 D3 D2 D1 D0

CTR2 (0D) 02H

0 P35 is Port Output*
1 P35 is TC16 Output

0 Disable T16 Time-Out Interrupt
1 Enable T16 Time-Out Interrupt

0 0 SCLK on T16
0 1 SCLK/2 on T16
1 0 SCLK/4 on T16
1 1 SCLK/8 on T16

* Default Setting After Reset

0 Disable T16 Data Capture Interrupt
1 Enable T16 Data Capture Interrupt

R 0 No T16 Time Out
R 1 T16 Time Out Occurs
W 0 No Effect
W 1 Reset Flag to 0

0 Modulo-N for T16
1 Single Pass for T16

R 0 T16 Disabled *
R 1 T16 Enabled
W 0 Stop T16
W 1 Enable T16

Transmit Mode

0 T16 Recognizes Edge
1 T16 Does Not Recognize Edge

Demodulator Mode

Z86L78
IR/Low-Voltage Microcontroller Zilog

2-52 DS97LVO0701

EXPANDED REGISTER FILE CONTROL REGISTERS (0F)

Figure 43. Stop-Mode Recovery Register

((F) 0BH: D6-D0 = Write Only, D7=Read Only

D7 D6 D5 D4 D3 D2 D1 D0

SMR (0F) 0B

SCLK/TCLK Divide-by-16
0 OFF
1 ON

Reserved (Must be 0)
Stop-Mode Recovery Source

000
001
010
011
100
101
110
111

Stop Delay
0 OFF
1 ON

Stop Recovery Level
0 Low
1 High

Stop Flag
0 POR
1 Stop Recovery**

* Default Setting After Reset
** Default Setting After Reset and Stop-Mode Recovery

**

*

*

*

*

POR Only
Reserved
P31
P32
P33
P27
P2 NOR 0-3
P2 NOR 0-7

Z86L78

Zilog IR/Low-Voltage Microcontroller

DS97LVO0701 2-53

1

Figure 44. Stop-Mode Recovery Register 2

((0F) DH: D2-D4, D6 Write Only)

D7 D6 D5 D4 D3 D2 D1 D0

SMR2 (0F) 0DH

Reserved (Must be 0)
Reserved (Must be 0)

Stop-Mode Recovery Source 2
000 POR only*
001 NAND P20, P21, P22, P23
010 NAND P20, P21, P22, P23, P24, P25, P26, P27
011 NOR P31, P32, P33
100 NAND P31, P32, P33
101 NOR P31, P32, P33, P00, P07
110 NAND P31, P32, P33, P00, P07
111 NAND P31, P32, P33, P20, P21, P22

Reserved (Must be 0)
Recovery Level

0 Low*
1 High

Reserved (Must be 0)

Note: If used in conjunction with SMR,
either of the two specified events will
cause a Stop-Mode Recovery.

*Default Setting After Reset

Z86L78
IR/Low-Voltage Microcontroller Zilog

2-54 DS97LVO0701

EXPANDED REGISTER FILE CONTROL REGISTERS (0F) (Continued)

Figure 45. Watch-Dog Timer Mode Register

((F) 0FH: Write Only)

D7 D6 D5 D4 D3 D2 D1 D0

WDTMR (0F) F

WDT TAP INT RC OSC External Clock
00 5 ms 256 TpC
01 10 ms 512 TpC
10 20 ms 1024 TpC
11 80 ms 4096 TpC

WDT During HALT
0 OFF
1 ON

WDT During STOP
0 OFF
1 ON

XTAL1/INT RC Select for WDT
0 On-Board RC
1 XTAL

Reserved (Must be 0)

* Default Setting After Reset

*

*

*

*

Figure 46. Port Configuration Register (PCON)

((0F) 0H: Write Only)

Reserved (Must be 1)

D7 D6 D5

D4

D3 D2 D1 D0

PCON (FH) 00H

Comparator Output Port 3
0 P34, P37 Standard Output*
1 P34, P37 Comparator Output

* Default Setting After Reset.
P34 comparator output only.

Z86L78

Zilog IR/Low-Voltage Microcontroller

DS97LVO0701 2-55

1

Z8 STANDARD CONTROL REGISTER DIAGRAMS

Figure 47. Port 3 Mode Register

(F7H: Write Only)

Figure 48. Port 0 and 1 Mode Register

(F8H: Write Only)

D7 D6 D5 D4 D3 D2 D1 D0

R247 P3M

0 Port 2 Open Drain*
1 Port 2 Push-pull

Reserved (Must be 0.)

0 P31 = Input (TIN)*
P36 = Output (T

OUT

)
1 P31 = /DAV2/RDY2
P36 = RDY2//DAV2

0 Digital*
1 Analog

** Effects P34 and P35 as well.
* Default setting after Reset.

Reserved (Must be 0.)

Reserved (Must be 0.)

D7 D6 D5 D4 D3 D2 D1 D0

R248 P01M

P00-P03 Mode
00 Output
01 Input*
1X A11-A8

P07-P04 Mode
00 Output
01 Input*
1X A15-A12

Notes:

Only P00 and P07 are available on Z86L71.
* Default Setting After Reset.

Reserved (Must be 0.)
Reserved (Must be 0.)

Reserved (Must be 0.)

Figure 49. Interrupt Priority Registers

((0) F9H: Write Only)

Figure 50. Interrupt Request Register

((0) FAH: Read/Write)

D7 D6 D5 D4 D3 D2 D1 D0

Interrupt Group Priority

000 Reserved
001 C > A > B
010 A > B > C
011 A > C > B
100 B > C > A
101 C > B > A
110 B > A > C
111 Reserved

IRQ0, IRQ2 Priority (Group B)

0 IRQ2 > IRQ0
1 IRQ0 > IRQ2

IRQ1, IRQ4 Priority (Group C)

0 IRQ1 > IRQ4
1 IRQ4 > IRQ1

Reserved (Must be 0)

R249 IPR

Reserved (Must be 0)

*Group A only has IRQ3 within it

D7 D6 D5 D4 D3 D2 D1 D0

R250 IRQ

Inter Edge
P31 ↓ P32 ↓ = 00
P31 ↓ P32 ↑ = 01
P31 ↑ P32 ↓ = 10
P31 ↑↓ P32 ↑↓ = 11

IRQ0 = P32 Input
IRQ1 = P33 Input
IRQ2 = P31 Input
IRQ3 = T16_OUT
IRQ4 = T8_OUT

Reserved (Must be 0)

Default Setting After Reset = 0000 0000

Z86L78
IR/Low-Voltage Microcontroller Zilog

2-56 DS97LVO0701

Figure 51. Interrupt Mask Register

((0( FBH: Read/Write)

Figure 52. Flag Register

((0) FCH: Read/Write

Figure 53. Register Pointer

((0) FDH: Read/Write)

D7 D6 D5 D4 D3 D2 D1 D0

Reserved (Must be 0)

1 Enables IRQ4-IRQ0
(D0 = IRQ0)

0 Master Interrupt Disable*
1 Master Interrupt Enable

R251 IMR

* Default Setting After Reset

Reserved (Must be 0)

D7 D6 D5 D4 D3 D2 D1 D0

User Flag F1
User Flag F2
Half Carry Flag
Decimal Adjust Flag
Overflow Flag
Sign Flag
Zero Flag
Carry Flag

R252 Flags

D7 D6 D5 D4 D3 D2 D1 D0

Expanded Register File Pointer
Working Register Pointer

R253 RP

Default Setting After Reset = 00H

Figure 54. Port 2 Mode Register

(F6H: Write Only)

Figure 55. Stack Pointer High

((0) FEH: Read/Write)

Figure 56. Stack Pointer Low

((0) FFH: Read/Write)

D7 D6 D5 D4 D3 D2 D1 D0

P27-P20 I/O Definition
0 Defines Bit as OUTPUT
1 Defines Bit as INPUT*

R246 P2M

*Default Setting After Reset

D7 D6 D5 D4 D3 D2 D1 D0

Stack Pointer Upper
Byte (SP15-SP8)

R254 RP

D7 D6 D5 D4 D3 D2 D1 D0

Stack Pointer Lower
Byte (SP7-SP0)

R255 SPL

Z86L78

Zilog IR/Low-Voltage Microcontroller

DS97LVO0701 2-57

1

PACKAGE INFORMATION

Figure 57. 20-Pin DIP Package Diagram

Z86L78
IR/Low-Voltage Microcontroller Zilog

2-58 DS97LVO0701

Figure 58. 20-Pin SOIC Package Diagram

Z86L78

Zilog IR/Low-Voltage Microcontroller

DS97LVO0701 2-59

1

ORDERING INFORMATION
Z86L78

8.0 MHz
20-pin DIP 20-pin SOIC

Z86L7808PSC Z86L7808SSC

Codes
Package

P = Plastic DIP
S = SOIC (Small Outline Integrated Circuit)

Temperature

8 = 8.0 MHz

Environmental

C = Plastic Standard

© 1997 by Zilog, Inc. All rights reserved. No part of this
document may be copied or reproduced in any form or by
any means without the prior written consent of Zilog, Inc.
The information in this document is subject to change
without notice. Devices sold by Zilog, Inc. are covered by
warranty and patent indemnification provisions appearing
in Zilog, Inc. Terms and Conditions of Sale only. Zilog, Inc.
makes no warranty, express, statutory, implied or by
description, regarding the information set forth herein or
regarding the freedom of the described devices from
intellectual property infringement. Zilog, Inc. makes no
warranty of merchantability or fitness for any purpose.
Zilog, Inc. shall not be responsible for any errors that may
appear in this document. Zilog, Inc. makes no commitment
to update or keep current the information contained in this
document.

Zilog’s products are not authorized for use as critical
components in life support devices or systems unless a
specific written agreement pertaining to such intended use
is executed between the customer and Zilog prior to use.
Life support devices or systems are those which are
intended for surgical implantation into the body, or which
sustains life whose failure to perform, when properly used
in accordance with instructions for use provided in the
labeling, can be reasonably expected to result in
significant injury to the user.

Zilog, Inc. 210 East Hacienda Ave.
Campbell, CA 95008-6600
Telephone [phone]
FAX [phone]
Internet: http://www.zilog.com

Example:

Z 86L78 08 P S C

Environmental Flow
Temperature
Package
Speed
Product Number
Zilog Prefix

is a Z86L78, 8 MHz, DIP, 0°C to +70°C, Plastic Standard Flow