Datasheet P89C52UBPN, P89C54UBAA, P89C51UBPN, P89C51UBAA, P89C54NBPN Datasheet (Philips)

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89C51/89C52/89C54/89C58

80C51 8-bit microcontroller family 4K/8K/16K/32K Flash

Product specification

Replaces Datasheets 89C51 of 1999 Apr 01 and 89C52/89C54/89C58 of 1999 Apr 01

1999 Oct 27

INTEGRATED CIRCUITS

Philips Semiconductors Product specification

89C51/89C52/89C54/89C58

80C51 8-bit microcontroller family 4K/8K/16K/32K Flash

1999 Oct 27 853–2148 22592

DESCRIPTION

The 89C51/89C52/89C54/89C58 contain a non-volatile FLASH program memory that is parallel programmable. For devices that are serial programmable (In System Programmable (ISP) with a boot loader), see the 89C51RC+/89C51RD+ datasheet.

Both families are Single-Chip 8-bit Microcontrollers manufactured in advanced CMOS process and are derivatives of the 80C51 microcontroller family. All the devices have the same instruction set as the 80C51.

SELECTION T ABLE FOR FLASH DEVICES

ROM/EPROM Memory Size

(X by 8)

RAM Size

(X by 8)

Programmable

Timer Counter

(PCA)

Hardware

Watchdog

Timer Multi-Time Programmable (MTP) devices: 89C51

4 k 128 No No

89C52/54/58

8 k/16 k/32 k 256 No No

Serial In-System Programmable devices:

89C51RC+

32 k 512 Yes Yes

89C51RD+

64 k 1024 Yes Yes

FEATURES

•80C51 Central Processing Unit

•On-chip FLASH Program Memory

•Speed up to 33 MHz

•Full static operation

•RAM expandable externally to 64 k bytes

•4 level priority interrupt

•6 interrupt sources

•Four 8-bit I/O ports

•Full-duplex enhanced UART

– Framing error detection – Automatic address recognition

•Power control modes

– Clock can be stopped and resumed – Idle mode – Power down mode

•Programmable clock out

•Second DPTR register

•Asynchronous port reset

•Low EMI (inhibit ALE)

•3 16-bit timers

•Wake up from power down by an external interrupt

ORDERING INFORMATION

MEMORY SIZE

4 k × 8

MEMORY SIZE

8 k × 8

MEMORY SIZE

16 k × 8

MEMORY SIZE

32 k × 8

TEMPERATURE

RANGE °C

AND PACKAGE

VOLTAGE

RANGE

FREQ.

(MHz)

DWG.

FLASH P89C51UBA A P89C52UBA A P89C54UBA A P89C58UBA A

0 to +70, Plastic

Leaded Chip Carrier

5 V 0 to 33 SOT187-2

FLASH P89C51UBP N P89C52UBP N P89C54UBP N P89C58UBP N

0 to +70, Plastic

Dual In-line Package

5 V 0 to 33 SOT129-1

FLASH P89C51UBB B P89C52UBB B P89C54UBB B P89C58UBB B

0 to +70, Plastic

Quad Flat Pack

5 V 0 to 33 QFP44

FLASH P89C51UFA A P89C52UFA A P89C54UFA A P89C58UFA A

–40 to +85, Plastic

Leaded Chip Carrier

5 V 0 to 33 SOT187-2

FLASH P89C51UFP N P89C52UFP N P89C54UFP N P89C58UFP N

–40 to +85, Plastic

Dual In-line Package

5 V 0 to 33 SOT129-1

FLASH P89C51UFB B P89C52UFB B P89C54UFB B P89C58UFB B

–40 to +85, Plastic

Quad Flat Pack

5 V 0 to 33 QFP44

NOTES:

1. Contact Philips Sales for availability.

2. SOT not assigned for this package outline.

P ART NUMBER DERIVATION

DEVICE NUMBER (P89CXX) OPERATING FREQUENCY, MAX (V) TEMPERATURE RANGE (B) PACKAGE (AA, BB, PN)

P89C51 FLASH P89C52 FLASH P89C54 FLASH P89C58 FLASH

U = 33 MHz

B = 0_C to 70_C

F = –40_C to 85_C

AA = PLCC BB = PQFP

PN = PDIP

Philips Semiconductors Product specification

89C51/89C52/89C54/89C58

80C51 8-bit microcontroller family 4K/8K/16K/32K Flash

1999 Oct 27

BLOCK DIAGRAM

SU01066

PSEN

EAV

ALE

RST

XTAL1 XTAL2

PORT 0

DRIVERS

PORT 2

DRIVERS

RAM ADDR REGISTER

RAM

PORT 0

LATCH

PORT 2

LATCH

FLASH

ACC

STACK

POINTER

TMP2

TMP1

ALU

TIMING

AND

CONTROL

INSTRUCTION

OSCILLATOR

PSW

PORT 1

LATCH

PORT 3

LATCH

PORT 1

DRIVERS

PORT 3

DRIVERS

PROGRAM

ADDRESS

BUFFER

INCRE-

MENTER

PROGRAM COUNTER

DPTR’S

MULTIPLE

P1.0–P1.7

P3.0–P3.7

P0.0–P0.7 P2.0–P2.7

SFRs

TIMERS

8 16

Philips Semiconductors Product specification

89C51/89C52/89C54/89C58

80C51 8-bit microcontroller family 4K/8K/16K/32K Flash

1999 Oct 27

LOGIC SYMBOL

PORT 0

PORT 1PORT 2

PORT 3

ADDRESS AND

DATA BUS

ADDRESS BUS

T2 T2EX

RxD

TxD INT0 INT1

T0 T1

SECONDARY FUNCTIONS

RST

EA/V

PSEN

ALE/PROG

XTAL1

XTAL2

SU00830

PIN CONFIGURA TIONS Dual In-Line Package Pin Functions

SU01063

1 2 3 4 5 6 7 8

9 10 11 12 13 14 15 16 17 18 19 20

T2/P1.0

T2EX/P1.1

P1.2 P1.3 P1.4 P1.5 P1.6

RST RxD/P3.0 TxD/P3.1

INT0

/P3.2

INT1

/P3.3 T0/P3.4 T1/P3.5

P1.7

/P3.6 RD

/P3.7

XTAL2 XTAL1

P2.0/A8

P2.1/A9

P2.2/A10

P2.3/A11

P2.4/A12

P2.5/A13

P2.6/A14

P2.7/A15

PSEN

ALE

P0.7/AD7

P0.6/AD6

P0.5/AD5

P0.4/AD4

P0.3/AD3

P0.2/AD2

P0.1/AD1

P0.0/AD0

DUAL

IN-LINE

PACKAGE

Ceramic and Plastic Leaded Chip Carrier Pin Functions

SU01062

LCC

6140

18 28

Pin Function

1 NIC* 2 P1.0/T2 3 P1.1/T2EX 4 P1.2 5 P1.3 6 P1.4 7 P1.5 8 P1.6

9 P1.7 10 RST 11 P3.0/RxD 12 NIC* 13 P3.1/TxD 14 P3.2/INT0 15 P3.3/INT1

Pin Function

16 P3.4/T0 17 P3.5/T1 18 P3.6/WR 19 P3.7/RD 20 XTAL2 21 XTAL1 22 V

23 NIC* 24 P2.0/A8 25 P2.1/A9 26 P2.2/A10 27 P2.3/A11 28 P2.4/A12 29 P2.5/A13 30 P2.6/A14

Pin Function

31 P2.7/A15 32 PSEN 33 ALE 34 NIC* 35 EA/V

36 P0.7/AD7 37 P0.6/AD6 38 P0.5/AD5 39 P0.4/AD4 40 P0.3/AD3 41 P0.2/AD2 42 P0.1/AD1 43 P0.0/AD0 44 V

* NO INTERNAL CONNECTION

Plastic Quad Flat Pack Pin Functions

SU01064

PQFP

44 34

12 22

Pin Function

1 P1.5 2 P1.6 3 P1.7 4 RST 5 P3.0/RxD 6 NIC* 7 P3.1/TxD 8 P3.2/INT0

9 P3.3/INT1 10 P3.4/T0 11 P3.5/T1 12 P3.6/WR 13 P3.7/RD 14 XTAL2 15 XTAL1

Pin Function

16 V

17 NIC* 18 P2.0/A8 19 P2.1/A9 20 P2.2/A10 21 P2.3/A11 22 P2.4/A12 23 P2.5/A13 24 P2.6/A14 25 P2.7/A15 26 PSEN 27 ALE 28 NIC* 29 EA

30 P0.7/AD7

Pin Function

31 P0.6/AD6 32 P0.5/AD5 33 P0.4/AD4 34 P0.3/AD3 35 P0.2/AD2 36 P0.1/AD1 37 P0.0/AD0 38 V

39 NIC* 40 P1.0/T2 41 P1.1/T2EX 42 P1.2 43 P1.3 44 P1.4

* NO INTERNAL CONNECTION

Philips Semiconductors Product specification

89C51/89C52/89C54/89C58

80C51 8-bit microcontroller family 4K/8K/16K/32K Flash

1999 Oct 27

PIN DESCRIPTIONS

PIN NUMBER

MNEMONIC DIP LCC QFP TYPE NAME AND FUNCTION

20 22 16 I Ground: 0 V reference.

40 44 38 I Power Supply: This is the power supply voltage for normal, idle, and power-down operation.

P0.0–0.7 39–32 43–36 37–30 I/O Port 0: Port 0 is an open-drain, bidirectional I/O port. Port 0 pins that have 1s written to

them float and can be used as high-impedance inputs. Port 0 is also the multiplexed low-order address and data bus during accesses to external program and data memory. In this application, it uses strong internal pull-ups when emitting 1s.

P1.0–P1.7 1–8 2–9 40–44,

1–3

I/O Port 1: Port 1 is an 8-bit bidirectional I/O port with internal pull-ups. Port 1 pins that have 1s

written to them are pulled high by the internal pull-ups and can be used as inputs. As inputs, port 1 pins that are externally pulled low will source current because of the internal pull-ups. (See DC Electrical Characteristics: I

). Alternate function for Port 1: 1 2 40 I/O T2 (P1.0): Timer/Counter2 external count input/clockout (see Programmable Clock-Out). 2 3 41 I T2EX (P1.1): Timer/Counter2 reload/capture/direction control.

P2.0–P2.7 21–28 24–31 18–25 I/O Port 2: Port 2 is an 8-bit bidirectional I/O port with internal pull-ups. Port 2 pins that have 1s

written to them are pulled high by the internal pull-ups and can be used as inputs. As inputs, port 2 pins that are externally being pulled low will source current because of the internal pull-ups. (See DC Electrical Characteristics: I

). Port 2 emits the high-order address byte during fetches from external program memory and during accesses to external data memory that use 16-bit addresses (MOVX @DPTR). In this application, it uses strong internal pull-ups when emitting 1s. During accesses to external data memory that use 8-bit addresses (MOV @Ri), port 2 emits the contents of the P2 special function register.

P3.0–P3.7 10–17 11,

13–195,7–13

I/O Port 3: Port 3 is an 8-bit bidirectional I/O port with internal pull-ups. Port 3 pins that have 1s

written to them are pulled high by the internal pull-ups and can be used as inputs. As inputs, port 3 pins that are externally being pulled low will source current because of the pull-ups. (See DC Electrical Characteristics: I

). Port 3 also serves the special features of the

89C51/89C52/89C54/89C58, as listed below:

10 11 5 I RxD (P3.0): Serial input port 11 13 7 O TxD (P3.1): Serial output port 12 14 8 I INT0 (P3.2): External interrupt 13 15 9 I INT1 (P3.3): External interrupt 14 16 10 I T0 (P3.4): Timer 0 external input 15 17 11 I T1 (P3.5): Timer 1 external input 16 18 12 O WR (P3.6): External data memory write strobe 17 19 13 O RD (P3.7): External data memory read strobe

RST 9 10 4 I Reset: A high on this pin for two machine cycles while the oscillator is running, resets the

device. An internal diffused resistor to V

permits a power-on reset using only an external

capacitor to V

ALE 30 33 27 O Address Latch Enable: Output pulse for latching the low byte of the address during an

access to external memory. In normal operation, ALE is emitted at a constant rate of 1/6 the oscillator frequency , and can be used for external timing or clocking. Note that one ALE pulse is skipped during each access to external data memory. ALE can be disabled by setting SFR auxiliary.0. With this bit set, ALE will be active only during a MOVX instruction.

PSEN 29 32 26 O Program Store Enable: The read strobe to external program memory. When executing

code from the external program memory, PSEN

is activated twice each machine cycle,

except that two PSEN

activations are skipped during each access to external data memory.

PSEN

is not activated during fetches from internal program memory.

EA/V

31 35 29 I External Access Enable/Programming Supply Voltage: EA must be externally held low

to enable the device to fetch code from external program memory locations 0000H to the maximum internal memory boundary. If EA

is held high, the device executes from internal program memory unless the program counter contains an address greater than 0FFFH for 4 k devices, 1FFFH for 8 k devices, 3FFFH for 16 k devices, and 7FFFH for 32 k devices. The value on the EA

pin is latched when RST is released and any subsequent changes

have no effect. This pin also receives the 12.00 V programming supply voltage (V

) during

FLASH programming.

XTAL1 19 21 15 I Crystal 1: Input to the inverting oscillator amplifier and input to the internal clock

generator circuits.

XTAL2 18 20 14 O Crystal 2: Output from the inverting oscillator amplifier.

NOTE: To avoid “latch-up” effect at power-on, the voltage on any pin (other than VPP) at any time must not be higher than VCC + 0.5 V or V

– 0.5 V , respectively.

Philips Semiconductors Product specification

89C51/89C52/89C54/89C58

80C51 8-bit microcontroller family 4K/8K/16K/32K Flash

1999 Oct 27

Table 1. 89C51/89C52/89C54/89C58 Special Function Registers

SYMBOL DESCRIPTION

DIRECT

ADDRESS

BIT ADDRESS, SYMBOL, OR ALTERNATIVE PORT FUNCTION

MSB LSB

RESET VALUE

ACC* Accumulator E0H E7 E6 E5 E4 E3 E2 E1 E0 00H AUXR# Auxiliary 8EH – – – – – – – AO xxxxxxx0B AUXR1# Auxiliary 1 A2H – – – – GF2 0 – DPS xxxx00x0B B* B register F0H F7 F6 F5 F4 F3 F2 F1 F0 00H DPTR: Data Pointer (2 bytes)

DPH Data Pointer High 83H 00H DPL Data Pointer Low 82H 00H

AF AE AD AC AB AA A9 A8

IE* Interrupt Enable A8H EA – ET2 ES ET1 EX1 ET0 EX0 0x000000B

BF BE BD BC BB BA B9 B8

IP* Interrupt Priority B8H – – PT2 PS PT1 PX1 PT0 PX0 xx000000B

B7 B6 B5 B4 B3 B2 B1 B0

IPH# Interrupt Priority High B7H – – PT2H PSH PT1H PX1H PT0H PX0H xx000000B

87 86 85 84 83 82 81 80

P0* Port 0 80H AD7 AD6 AD5 AD4 AD3 AD2 AD1 AD0 FFH

97 96 95 94 93 92 91 90

P1* Port 1 90H – – – – – – T2EX T2 FFH

A7 A6 A5 A4 A3 A2 A1 A0

P2* Port 2 A0H AD15 AD14 AD13 AD12 AD1 1 AD10 AD9 AD8 FFH

B7 B6 B5 B4 B3 B2 B1 B0

P3* Port 3 B0H RD WR T1 T0 INT1 INT0 TxD RxD FFH

PCON#1Power Control 87H SMOD1 SMOD0 – POF

GF1 GF0 PD IDL 00xxx000B

D7 D6 D5 D4 D3 D2 D1 D0

PSW* Program Status Word D0H CY AC F0 RS1 RS0 OV – P 000000x0B

RACAP2H# Timer 2 Capture High CBH 00H RACAP2L# Timer 2 Capture Low CAH 00H

SADDR# Slave Address A9H 00H SADEN# Slave Address Mask B9H 00H

SBUF Serial Data Buffer 99H xxxxxxxxB

9F 9E 9D 9C 9B 9A 99 98

SCON* Serial Control 98H

SM0/FE

SM1 SM2 REN TB8 RB8 TI RI 00H

SP Stack Pointer 81H 07H

8F 8E 8D 8C 8B 8A 89 88

TCON* Timer Control 88H TF1 TR1 TF0 TR0 IE1 IT1 IE0 IT0 00H

CF CE CD CC CB CA C9 C8 T2CON* Timer 2 Control C8H TF2 EXF2 RCLK TCLK EXEN2 TR2 C/T2 CP/RL2 00H T2MOD# Timer 2 Mode Control C9H – – – – – – T2OE DCEN xxxxxx00B

TH0 Timer High 0 8CH 00H TH1 Timer High 1 8DH 00H TH2# Timer High 2 CDH 00H TL0 Timer Low 0 8AH 00H TL1 Timer Low 1 8BH 00H TL2# Timer Low 2 CCH 00H

TMOD T imer Mode 89H GATE C/T M1 M0 GATE C/T M1 M0 00H

* SFRs are bit addressable. # SFRs are modified from or added to the 80C51 SFRs. – Reserved bits.

1. Reset value depends on reset source.

2. Bit will not be affected by reset.

Philips Semiconductors Product specification

89C51/89C52/89C54/89C58

80C51 8-bit microcontroller family 4K/8K/16K/32K Flash

1999 Oct 27

FLASH EPROM MEMORY General Description

The 89C51/89C52/89C54/89C58 FLASH reliably stores memory contents even after 100 erase and program cycles. The cell is designed to optimize the erase and programming mechanisms. In addition, the combination of advanced tunnel oxide processing and low internal electric fields for erase and programming operations produces reliable cycling.

Features

•FLASH EPROM internal program memory with Chip Erase

•Up to 64 k byte external program memory if the internal program

memory is disabled (EA

= 0)

•Programmable security bits

•100 minimum erase/program cycles for each byte

•10 year minimum data retention

•Programming support available from many popular vendors

OSCILLA T OR CHARACTERISTICS

XTAL1 and XTAL2 are the input and output, respectively, of an inverting amplifier. The pins can be configured for use as an on-chip oscillator.

To drive the device from an external clock source, XTAL1 should be driven while XTAL2 is left unconnected. There are no requirements on the duty cycle of the external clock signal, because the input to the internal clock circuitry is through a divide-by-two flip-flop. However, minimum and maximum high and low times specified in the data sheet must be observed.

RESET

A reset is accomplished by holding the RST pin high for at least two machine cycles (24 oscillator periods), while the oscillator is running. To insure a good power-on reset, the RST pin must be high long enough to allow the oscillator time to start up (normally a few milliseconds) plus two machine cycles. At power-on, the voltage on V

and RST must come up at the same time for a proper start-up. Ports 1, 2, and 3 will asynchronously be driven to their reset condition when a voltage above V

IH1

(min.) is applied to RESET.

The value on the EA

pin is latched when RST is deasserted and has

no further effect.

Philips Semiconductors Product specification

89C51/89C52/89C54/89C58

80C51 8-bit microcontroller family 4K/8K/16K/32K Flash

1999 Oct 27

LOW POWER MODES Stop Clock Mode

The static design enables the clock speed to be reduced down to 0 MHz (stopped). When the oscillator is stopped, the RAM and Special Function Registers retain their values. This mode allows step-by-step utilization and permits reduced system power consumption by lowering the clock frequency down to any value. For lowest power consumption the Power Down mode is suggested.

Idle Mode

In the idle mode (see Table 2), the CPU puts itself to sleep while all of the on-chip peripherals stay active. The instruction to invoke the idle mode is the last instruction executed in the normal operating mode before the idle mode is activated. The CPU contents, the on-chip RAM, and all of the special function registers remain intact during this mode. The idle mode can be terminated either by any enabled interrupt (at which time the process is picked up at the interrupt service routine and continued), or by a hardware reset which starts the processor in the same manner as a power-on reset.

Power-Down Mode

To save even more power, a Power Down mode (see Table 2) can be invoked by software. In this mode, the oscillator is stopped and the instruction that invoked Power Down is the last instruction executed. The on-chip RAM and Special Function Registers retain their values down to 2.0 V and care must be taken to return V

to the minimum specified operating voltages before the Power Down Mode is terminated.

Either a hardware reset or external interrupt can be used to exit from Power Down. Reset redefines all the SFRs but does not change the on-chip RAM. An external interrupt allows both the SFRs and the on-chip RAM to retain their values.

To properly terminate Power Down the reset or external interrupt should not be executed before V

is restored to its normal operating level and must be held active long enough for the oscillator to restart and stabilize (normally less than 10ms).

With an external interrupt, INT0 and INT1 must be enabled and configured as level-sensitive. Holding the pin low restarts the oscillator but bringing the pin back high completes the exit. Once the interrupt is serviced, the next instruction to be executed after RETI will be the one following the instruction that put the device into Power Down.

Design Consideration

•When the idle mode is terminated by a hardware reset, the device

normally resumes program execution, from where it left off, up to two machine cycles before the internal reset algorithm takes control. On-chip hardware inhibits access to internal RAM in this event, but access to the port pins is not inhibited. To eliminate the possibility of an unexpected write when Idle is terminated by reset, the instruction following the one that invokes Idle should not be one that writes to a port pin or to external memory.

ONCE Mode

The ONCE (“On-Circuit Emulation”) Mode facilitates testing and debugging of systems without the device having to be removed from the circuit. The ONCE Mode is invoked by:

1. Pull ALE low while the device is in reset and PSEN

is high;

2. Hold ALE low as RST is deactivated. While the device is in ONCE Mode, the Port 0 pins go into a float

state, and the other port pins and ALE and PSEN

are weakly pulled high. The oscillator circuit remains active. While the device is in this mode, an emulator or test CPU can be used to drive the circuit. Normal operation is restored when a normal reset is applied.

Programmable Clock-Out

A 50% duty cycle clock can be programmed to come out on P1.0. This pin, besides being a regular I/O pin, has two alternate functions. It can be programmed:

1. to input the external clock for Timer/Counter 2, or

2. to output a 50% duty cycle clock ranging from 61Hz to 4MHz at a

16MHz operating frequency.

To configure the Timer/Counter 2 as a clock generator, bit C/T2 (in T2CON) must be cleared and bit T20E in T2MOD must be set. Bit TR2 (T2CON.2) also must be set to start the timer.

The Clock-Out frequency depends on the oscillator frequency and the reload value of Timer 2 capture registers (RCAP2H, RCAP2L) as shown in this equation:

Oscillator Frequency

4 (65536 * RCAP2H,RCAP2L)

Where (RCAP2H,RCAP2L) = the content of RCAP2H and RCAP2L taken as a 16-bit unsigned integer.

In the Clock-Out mode Timer 2 roll-overs will not generate an interrupt. This is similar to when it is used as a baud-rate generator. It is possible to use Timer 2 as a baud-rate generator and a clock generator simultaneously. Note, however, that the baud-rate and the Clock-Out frequency will be the same.

Table 2. External Pin Status During Idle and Power-Down Mode

MODE PROGRAM MEMORY ALE PSEN PORT 0 PORT 1 PORT 2 PORT 3

Idle Internal 1 1 Data Data Data Data Idle External 1 1 Float Data Address Data Power-down Internal 0 0 Data Data Data Data Power-down External 0 0 Float Data Data Data

Philips Semiconductors Product specification

89C51/89C52/89C54/89C58

80C51 8-bit microcontroller family 4K/8K/16K/32K Flash

1999 Oct 27

TIMER 2 OPERA TION Timer 2

Timer 2 is a 16-bit Timer/Counter which can operate as either an event timer or an event counter, as selected by C/T

2* in the special function register T2CON (see Figure 1). Timer 2 has three operating modes: Capture, Auto-reload (up or down counting), and Baud Rate Generator, which are selected by bits in the T2CON as shown in Table 3.

Capture Mode

In the capture mode there are two options which are selected by bit EXEN2 in T2CON. If EXEN2=0, then timer 2 is a 16-bit timer or counter (as selected by C/T

2* in T2CON) which, upon overflowing sets bit TF2, the timer 2 overflow bit. This bit can be used to generate an interrupt (by enabling the Timer 2 interrupt bit in the IE register). If EXEN2= 1, Timer 2 operates as described above, but with the added feature that a 1- to -0 transition at external input T2EX causes the current value in the Timer 2 registers, TL2 and TH2, to be captured into registers RCAP2L and RCAP2H, respectively. In addition, the transition at T2EX causes bit EXF2 in T2CON to be set, and EXF2 like TF2 can generate an interrupt (which vectors to the same location as Timer 2 overflow interrupt. The Timer 2 interrupt service routine can interrogate TF2 and EXF2 to determine which event caused the interrupt). The capture mode is illustrated in Figure 2 (There is no reload value for TL2 and TH2 in this mode. Even when a capture event occurs from T2EX, the counter keeps on counting T2EX pin transitions or osc/12 pulses.).

Auto-Reload Mode (Up or Down Counter)

In the 16-bit auto-reload mode, Timer 2 can be configured (as either a timer or counter [C/T

2* in T2CON]) then programmed to count up or down. The counting direction is determined by bit DCEN (Down Counter Enable) which is located in the T2MOD register (see

Figure 3). When reset is applied the DCEN=0 which means Timer 2 will default to counting up. If DCEN bit is set, Timer 2 can count up or down depending on the value of the T2EX pin.

Figure 4 shows Timer 2 which will count up automatically since DCEN=0. In this mode there are two options selected by bit EXEN2 in T2CON register. If EXEN2=0, then T imer 2 counts up to 0FFFFH and sets the TF2 (Overflow Flag) bit upon overflow. This causes the Timer 2 registers to be reloaded with the 16-bit value in RCAP2L and RCAP2H. The values in RCAP2L and RCAP2H are preset by software means.

If EXEN2=1, then a 16-bit reload can be triggered either by an overflow or by a 1-to-0 transition at input T2EX. This transition also sets the EXF2 bit. The Timer 2 interrupt, if enabled, can be generated when either TF2 or EXF2 are 1.

In Figure 5 DCEN=1 which enables Timer 2 to count up or down. This mode allows pin T2EX to control the direction of count. When a logic 1 is applied at pin T2EX Timer 2 will count up. Timer 2 will overflow at 0FFFFH and set the TF2 flag, which can then generate an interrupt, if the interrupt is enabled. This timer overflow also causes the 16–bit value in RCAP2L and RCAP2H to be reloaded into the timer registers TL2 and TH2.

When a logic 0 is applied at pin T2EX this causes Timer 2 to count down. The timer will underflow when TL2 and TH2 become equal to the value stored in RCAP2L and RCAP2H. Timer 2 underflow sets the TF2 flag and causes 0FFFFH to be reloaded into the timer registers TL2 and TH2.

The external flag EXF2 toggles when Timer 2 underflows or overflows. This EXF2 bit can be used as a 17th bit of resolution if needed. The EXF2 flag does not generate an interrupt in this mode of operation.

(MSB) (LSB)

Symbol Position Name and Significance

TF2 T2CON.7 Timer 2 overflow flag set by a Timer 2 overflow and must be cleared by software. TF2 will not be set

when either RCLK or TCLK = 1.

EXF2 T2CON.6 Timer 2 external flag set when either a capture or reload is caused by a negative transition on T2EX and

EXEN2 = 1. When Timer 2 interrupt is enabled, EXF2 = 1 will cause the CPU to vector to the Timer 2 interrupt routine. EXF2 must be cleared by software. EXF2 does not cause an interrupt in up/down counter mode (DCEN = 1).

RCLK T2CON.5 Receive clock flag. When set, causes the serial port to use Timer 2 overflow pulses for its receive clock

in modes 1 and 3. RCLK = 0 causes Timer 1 overflow to be used for the receive clock.

TCLK T2CON.4 Transmit clock flag. When set, causes the serial port to use Timer 2 overflow pulses for its transmit clock

in modes 1 and 3. TCLK = 0 causes Timer 1 overflows to be used for the transmit clock.

EXEN2 T2CON.3 Timer 2 external enable flag. When set, allows a capture or reload to occur as a result of a negative

transition on T2EX if Timer 2 is not being used to clock the serial port. EXEN2 = 0 causes Timer 2 to

ignore events at T2EX. TR2 T2CON.2 Start/stop control for Timer 2. A logic 1 starts the timer. C/T2

T2CON.1 Timer or counter select. (Timer 2)

0 = Internal timer (OSC/12) 1 = External event counter (falling edge triggered).

CP/RL2

T2CON.0 Capture/Reload flag. When set, captures will occur on negative transitions at T2EX if EXEN2 = 1. When

cleared, auto-reloads will occur either with Timer 2 overflows or negative transitions at T2EX when

EXEN2 = 1. When either RCLK = 1 or TCLK = 1, this bit is ignored and the timer is forced to auto-reload

on Timer 2 overflow .

TF2 EXF2 RCLK TCLK EXEN2 TR2 C/T2

CP/RL2

SU00728

Figure 1. Timer/Counter 2 (T2CON) Control Register

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80C51 8-bit microcontroller family 4K/8K/16K/32K Flash

1999 Oct 27

Table 3. Timer 2 Operating Modes

RCLK + TCLK CP/RL2 TR2 MODE

0 0 1 16-bit Auto-reload 0 1 1 16-bit Capture 1 X 1 Baud rate generator X X 0 (off)

OSC

÷ 12

C/T2

= 0

C/T2

= 1

TR2

Control

TL2

(8-bits)

TH2

(8-bits)

TF2

RCAP2L RCAP2H

EXEN2

Control

EXF2

Timer 2

Interrupt

T2EX Pin

Transition

Detector

T2 Pin

Capture

SU00066

Figure 2. Timer 2 in Capture Mode

Not Bit Addressable

Symbol Function

— Not implemented, reserved for future use.* T2OE Timer 2 Output Enable bit. DCEN Down Count Enable bit. When set, this allows Timer 2 to be configured as an up/down counter.

— — — — — — T2OE DCEN

SU00729

76543210

* User software should not write 1s to reserved bits. These bits may be used in future 8051 family products to invoke new features.

In that case, the reset or inactive value of the new bit will be 0, and its active value will be 1. The value read from a reserved bit is indeterminate.

Bit

T2MOD Address = 0C9H Reset Value = XXXX XX00B

Figure 3. Timer 2 Mode (T2MOD) Control Register

Philips Semiconductors Product specification

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80C51 8-bit microcontroller family 4K/8K/16K/32K Flash

1999 Oct 27

OSC

÷ 12

C/T2 = 0

C/T2

= 1

TR2

CONTROL

TL2

(8-BITS)

TH2

(8-BITS)

TF2

RCAP2L RCAP2H

EXEN2

CONTROL

EXF2

TIMER 2

INTERRUPT

T2EX PIN

TRANSITION

DETECTOR

T2 PIN

RELOAD

SU00067

Figure 4. Timer 2 in Auto-Reload Mode (DCEN = 0)

÷12

C/T2 = 0

C/T2

= 1

TL2 TH2

TR2

CONTROL

T2 PIN

SU00730

FFH FFH

RCAP2L RCAP2H

(UP COUNTING RELOAD VALUE) T2EX PIN

TF2

INTERRUPT

COUNT DIRECTION 1 = UP 0 = DOWN

EXF2

OVERFLOW

(DOWN COUNTING RELOAD VALUE)

TOGGLE

OSC

Figure 5. Timer 2 Auto Reload Mode (DCEN = 1)

Philips Semiconductors Product specification

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80C51 8-bit microcontroller family 4K/8K/16K/32K Flash

1999 Oct 27

OSC

÷ 2

C/T2 = 0

C/T2

= 1

TR2

Control

TL2

(8-bits)

TH2

(8-bits)

÷ 16

RCAP2L RCAP2H

EXEN2

Control

EXF2

Timer 2

Interrupt

T2EX Pin

Transition

Detector

T2 Pin

Reload

NOTE: OSC. Freq. is divided by 2, not 12.

÷ 2

“0” “1”

RX Clock

÷ 16 TX Clock

“0”“1”

Timer 1

Overflow

Note availability of additional external interrupt.

SMOD

RCLK

TCLK

SU00068

Figure 6. Timer 2 in Baud Rate Generator Mode

T able 4. Timer 2 Generated Commonly Used

Baud Rates

Timer 2

Baud Rate

Osc Freq

RCAP2H RCAP2L

375 k 12 MHz FF FF

9.6 k 12 MHz FF D9

2.8 k 12 MHz FF B2

2.4 k 12 MHz FF 64

1.2 k 12 MHz FE C8 300 12 MHz FB 1E 110 12 MHz F2 AF 300 6 MHz FD 8F 110 6 MHz F9 57

Baud Rate Generator Mode

Bits TCLK and/or RCLK in T2CON (Table 4) allow the serial port transmit and receive baud rates to be derived from either Timer 1 or Timer 2. When TCLK= 0, Timer 1 is used as the serial port transmit baud rate generator . When TCLK= 1, Timer 2 is used as the serial port transmit baud rate generator. RCLK has the same effect for the serial port receive baud rate. With these two bits, the serial port can have different receive and transmit baud rates – one generated by Timer 1, the other by Timer 2.

Figure 6 shows the Timer 2 in baud rate generation mode. The baud rate generation mode is like the auto-reload mode, in that a rollover in TH2 causes the Timer 2 registers to be reloaded with the 16-bit value in registers RCAP2H and RCAP2L, which are preset by software.

The baud rates in modes 1 and 3 are determined by Timer 2’s overflow rate given below:

Modes 1 and 3 Baud Rates +

Timer 2 Overflow Rate

The timer can be configured for either “timer” or “counter” operation. In many applications, it is configured for “timer” operation (C/T

2*=0). Timer operation is different for Timer 2 when it is being used as a baud rate generator.

Usually, as a timer it would increment every machine cycle (i.e., 1/12 the oscillator frequency). As a baud rate generator, it increments every state time (i.e., 1/2 the oscillator frequency). Thus the baud rate formula is as follows:

Oscillator Frequency

[32 [65536 * (RCAP2H,RCAP2L)]]

Modes 1 and 3 Baud Rates =

Where: (RCAP2H, RCAP2L) = The content of RCAP2H and RCAP2L taken as a 16-bit unsigned integer.

The Timer 2 as a baud rate generator mode shown in Figure 6, is valid only if RCLK and/or TCLK = 1 in T2CON register. Note that a rollover in TH2 does not set TF2, and will not generate an interrupt. Thus, the Timer 2 interrupt does not have to be disabled when Timer 2 is in the baud rate generator mode. Also if the EXEN2 (T2 external enable flag) is set, a 1-to-0 transition in T2EX (Timer/counter 2 trigger input) will set EXF2 (T2 external flag) but will not cause a reload from (RCAP2H, RCAP2L) to (TH2,TL2). Therefore when Timer 2 is in use as a baud rate generator, T2EX can be used as an additional external interrupt, if needed.

Philips Semiconductors Product specification

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80C51 8-bit microcontroller family 4K/8K/16K/32K Flash

1999 Oct 27

When Timer 2 is in the baud rate generator mode, one should not try to read or write TH2 and TL2. As a baud rate generator, T imer 2 is incremented every state time (osc/2) or asynchronously from pin T2; under these conditions, a read or write of TH2 or TL2 may not be accurate. The RCAP2 registers may be read, but should not be written to, because a write might overlap a reload and cause write and/or reload errors. The timer should be turned off (clear TR2) before accessing the Timer 2 or RCAP2 registers.

Table 4 shows commonly used baud rates and how they can be obtained from Timer 2.

Summary Of Baud Rate Equations

Timer 2 is in baud rate generating mode. If Timer 2 is being clocked through pin T2(P1.0) the baud rate is:

Baud Rate +

Timer 2 Overflow Rate

If Timer 2 is being clocked internally , the baud rate is:

Baud Rate +

OSC

[32 [65536 * (RCAP2H,RCAP2L)]]

Where f

OSC

= Oscillator Frequency

To obtain the reload value for RCAP2H and RCAP2L, the above equation can be rewritten as:

RCAP2H,RCAP2L + 65536 *

OSC

32 Baud Rate

Timer/Counter 2 Set-up

Except for the baud rate generator mode, the values given for T2CON do not include the setting of the TR2 bit. Therefore, bit TR2 must be set, separately, to turn the timer on. see Table 5 for set-up of Timer 2 as a timer. Also see Table 6 for set-up of Timer 2 as a counter.

Table 5. Timer 2 as a Timer

T2CON

MODE

INTERNAL CONTROL

(Note 1)

EXTERNAL CONTROL

(Note 2)

16-bit Auto-Reload 00H 08H 16-bit Capture 01H 09H Baud rate generator receive and transmit same baud rate 34H 36H Receive only 24H 26H Transmit only 14H 16H

Table 6. Timer 2 as a Counter

TMOD

MODE

INTERNAL CONTROL

(Note 1)

EXTERNAL CONTROL

(Note 2)

16-bit 02H 0AH Auto-Reload 03H 0BH

NOTES:

1. Capture/reload occurs only on timer/counter overflow.

2. Capture/reload occurs on timer/counter overflow and a 1-to-0 transition on T2EX (P1.1) pin except when Timer 2 is used in the baud rate generator mode.

Philips Semiconductors Product specification

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80C51 8-bit microcontroller family 4K/8K/16K/32K Flash

1999 Oct 27

Enhanced UART

The UART operates in all of the usual modes that are described in the first section of

Data Handbook IC20, 80C51-Based 8-Bit

Microcontrollers

. In addition the UART can perform framing error detect by looking for missing stop bits, and automatic address recognition. The UART also fully supports multiprocessor communication as does the standard 80C51 UART.

When used for framing error detect the UART looks for missing stop bits in the communication. A missing bit will set the FE bit in the SCON register. The FE bit shares the SCON.7 bit with SM0 and the function of SCON.7 is determined by PCON.6 (SMOD0) (see Figure 7). If SMOD0 is set then SCON.7 functions as FE. SCON.7 functions as SM0 when SMOD0 is cleared. When used as FE SCON.7 can only be cleared by software. Refer to Figure 8.

Automatic Address Recognition

Automatic Address Recognition is a feature which allows the UART to recognize certain addresses in the serial bit stream by using hardware to make the comparisons. This feature saves a great deal of software overhead by eliminating the need for the software to examine every serial address which passes by the serial port. This feature is enabled by setting the SM2 bit in SCON. In the 9 bit UART modes, mode 2 and mode 3, the Receive Interrupt flag (RI) will be automatically set when the received byte contains either the “Given” address or the “Broadcast” address. The 9 bit mode requires that the 9th information bit is a 1 to indicate that the received information is an address and not data. Automatic address recognition is shown in Figure 9.

The 8 bit mode is called Mode 1. In this mode the RI flag will be set if SM2 is enabled and the information received has a valid stop bit following the 8 address bits and the information is either a Given or Broadcast address.

Mode 0 is the Shift Register mode and SM2 is ignored. Using the Automatic Address Recognition feature allows a master to

selectively communicate with one or more slaves by invoking the Given slave address or addresses. All of the slaves may be contacted by using the Broadcast address. Two special Function Registers are used to define the slave’s address, SADDR, and the address mask, SADEN. SADEN is used to define which bits in the SADDR are to b used and which bits are “don’t care”. The SADEN mask can be logically ANDed with the SADDR to create the “Given” address which the master will use for addressing each of the slaves. Use of the Given address allows multiple slaves to be recognized while excluding others. The following examples will help to show the versatility of this scheme:

Slave 0 SADDR = 1100 0000

SADEN = 1111 1101 Given = 1100 00X0

Slave 1 SADDR = 1100 0000

SADEN = 1111 1110 Given = 1100 000X

In the above example SADDR is the same and the SADEN data is used to differentiate between the two slaves. Slave 0 requires a 0 in bit 0 and it ignores bit 1. Slave 1 requires a 0 in bit 1 and bit 0 is ignored. A unique address for Slave 0 would be 1100 0010 since slave 1 requires a 0 in bit 1. A unique address for slave 1 would be 1100 0001 since a 1 in bit 0 will exclude slave 0. Both slaves can be selected at the same time by an address which has bit 0 = 0 (for slave 0) and bit 1 = 0 (for slave 1). Thus, both could be addressed with 1100 0000.

In a more complex system the following could be used to select slaves 1 and 2 while excluding slave 0:

Slave 0 SADDR = 1100 0000

SADEN = 1111 1001 Given = 1100 0XX0

Slave 1 SADDR = 1110 0000

SADEN = 1111 1010 Given = 1110 0X0X

Slave 2 SADDR = 1110 0000

SADEN = 1111 1100 Given = 1110 00XX

In the above example the differentiation among the 3 slaves is in the lower 3 address bits. Slave 0 requires that bit 0 = 0 and it can be uniquely addressed by 1110 01 10. Slave 1 requires that bit 1 = 0 and it can be uniquely addressed by 1110 and 0101. Slave 2 requires that bit 2 = 0 and its unique address is 1110 0011. To select Slaves 0 and 1 and exclude Slave 2 use address 1110 0100, since it is necessary to make bit 2 = 1 to exclude slave 2.

The Broadcast Address for each slave is created by taking the logical OR of SADDR and SADEN. Zeros in this result are trended as don’t-cares. In most cases, interpreting the don’t-cares as ones, the broadcast address will be FF hexadecimal.

Upon reset SADDR (SFR address 0A9H) and SADEN (SFR address 0B9H) are leaded with 0s. This produces a given address of all “don’t cares” as well as a Broadcast address of all “don’t cares”. This effectively disables the Automatic Addressing mode and allows the microcontroller to use standard 80C51 type UART drivers which do not make use of this feature.

Philips Semiconductors Product specification

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80C51 8-bit microcontroller family 4K/8K/16K/32K Flash

1999 Oct 27

SCON Address = 98H

Reset Value = 0000 0000B

SM0/FE SM1 SM2 REN TB8 RB8 Tl Rl

Bit Addressable

(SMOD0 = 0/1)*

Symbol Function FE Framing Error bit. This bit is set by the receiver when an invalid stop bit is detected. The FE bit is not cleared by valid

frames but should be cleared by software. The SMOD0 bit must be set to enable access to the FE bit.

SM0 Serial Port Mode Bit 0, (SMOD0 must = 0 to access bit SM0) SM1 Serial Port Mode Bit 1

SM0 SM1 Mode Description Baud Rate**

0 0 0 shift register f

OSC

/12 0 1 1 8-bit UART variable 1 0 2 9-bit UART f

OSC

/64 or f

OSC

/32

1 1 3 9-bit UART variable

SM2 Enables the Automatic Address Recognition feature in Modes 2 or 3. If SM2 = 1 then Rl will not be set unless the

received 9th data bit (RB8) is 1, indicating an address, and the received byte is a Given or Broadcast Address. In Mode 1, if SM2 = 1 then Rl will not be activated unless a valid stop bit was received, and the received byte is a Given or Broadcast Address. In Mode 0, SM2 should be 0.

REN Enables serial reception. Set by software to enable reception. Clear by software to disable reception. TB8 The 9th data bit that will be transmitted in Modes 2 and 3. Set or clear by software as desired. RB8 In modes 2 and 3, the 9th data bit that was received. In Mode 1, if SM2 = 0, RB8 is the stop bit that was received.

In Mode 0, RB8 is not used.

Tl Transmit interrupt flag. Set by hardware at the end of the 8th bit time in Mode 0, or at the beginning of the stop bit in the

other modes, in any serial transmission. Must be cleared by software.

Rl Receive interrupt flag. Set by hardware at the end of the 8th bit time in Mode 0, or halfway through the stop bit time in

the other modes, in any serial reception (except see SM2). Must be cleared by software.

NOTE:

*SMOD0 is located at PCON6. **f

OSC

= oscillator frequency

SU00043

Bit: 76543210

Figure 7. SCON: Serial Port Control Register

Philips Semiconductors Product specification

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80C51 8-bit microcontroller family 4K/8K/16K/32K Flash

1999 Oct 27

SMOD1 SMOD0 – POF GF1 GF0 PD IDL

PCON

(87H)

SM0 / FE SM1 SM2 REN TB8 RB8 TI RI

SCON

(98H)

D0 D1 D2 D3 D4 D5 D6 D7 D8

STOP

BIT

DATA BYTE

ONLY IN

MODE 2, 3

START

BIT

SET FE BIT IF STOP BIT IS 0 (FRAMING ERROR)

SM0 TO UART MODE CONTROL

0 : SCON.7 = SM0 1 : SCON.7 = FE

SU01191

Figure 8. UART Framing Error Detection

SM0 SM1 SM2 REN TB8 RB8 TI RI

SCON

(98H)

D0 D1 D2 D3 D4 D5 D6 D7 D8

1 1

1 0

COMPARATOR

11 X

RECEIVED ADDRESS D0 TO D7

PROGRAMMED ADDRESS

IN UART MODE 2 OR MODE 3 AND SM2 = 1: INTERRUPT IF REN=1, RB8=1 AND “RECEIVED ADDRESS” = “PROGRAMMED ADDRESS” – WHEN OWN ADDRESS RECEIVED, CLEAR SM2 TO RECEIVE DATA BYTES – WHEN ALL DATA BYTES HAVE BEEN RECEIVED: SET SM2 TO WAIT FOR NEXT ADDRESS.

SU00045

Figure 9. UART Multiprocessor Communication, Automatic Address Recognition

Philips Semiconductors Product specification

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Interrupt Priority Structure

The 89C51/89C52/89C54/89C58 have a 6-source four-level interrupt structure.

There are 3 SFRs associated with the four-level interrupt. They are the IE, IP, and IPH. (See Figures 10, 11, and 12.) The IPH (Interrupt Priority High) register makes the four-level interrupt structure possible. The IPH is located at SFR address B7H. The structure of the IPH register and a description of its bits is shown in Figure 12.

The function of the IPH SFR is simple and when combined with the IP SFR determines the priority of each interrupt. The priority of each interrupt is determined as shown in the following table:

PRIORITY BITS

IPH.x IP.x

INTERRUPT PRIORITY LEVEL

0 0 Level 0 (lowest priority) 0 1 Level 1 1 0 Level 2 1 1 Level 3 (highest priority)

There are four interrupt levels rather than two as on the 80C51. An interrupt will be serviced as long as an interrupt of equal or higher priority is not already being serviced. If an interrupt of equal or higher level priority is being serviced, the new interrupt will wait until it is finished before being serviced. If a lower priority level interrupt is being serviced, it will be stopped and the new interrupt serviced. When the new interrupt is finished, the lower priority level interrupt that was stopped will be completed.

Table 7. Interrupt Table

SOURCE POLLING PRIORITY REQUEST BITS HARDWARE CLEAR? VECTOR ADDRESS

X0 1 IE0 N (L)1Y (T)

03H T0 2 TP0 Y 0BH X1 3 IE1 N (L) Y (T) 13H T1 4 TF1 Y 1BH SP 5 RI, TI N 23H T2 6 TF2, EXF2 N 2BH

NOTES:

1. L = Level activated

2. T = Transition activated

EX0IE (0A8H)

Enable Bit = 1 enables the interrupt. Enable Bit = 0 disables it.

BIT SYMBOL FUNCTION

IE.7 EA Global disable bit. If EA = 0, all interrupts are disabled. If EA = 1, each interrupt can be individually

enabled or disabled by setting or clearing its enable bit. IE.6 — Not implemented. Reserved for future use. IE.5 ET2 Timer 2 interrupt enable bit. IE.4 ES Serial Port interrupt enable bit. IE.3 ET1 Timer 1 interrupt enable bit. IE.2 EX1 External interrupt 1 enable bit. IE.1 ET0 Timer 0 interrupt enable bit. IE.0 EX0 External interrupt 0 enable bit.

SU00571

ET0EX1ET1ESET2—EA

01234567

Figure 10. IE Registers

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PX0IP (0B8H)

Priority Bit = 1 assigns higher priority Priority Bit = 0 assigns lower priority

BIT SYMBOL FUNCTION

IP.7 — Not implemented, reserved for future use. IP.6 — Not implemented, reserved for future use. IP.5 PT2 Timer 2 interrupt priority bit. IP.4 PS Serial Port interrupt priority bit. IP.3 PT1 Timer 1 interrupt priority bit. IP.2 PX1 External interrupt 1 priority bit. IP.1 PT0 Timer 0 interrupt priority bit. IP.0 PX0 External interrupt 0 priority bit.

SU00572

PT0PX1PT1PSPT2——

01234567

Figure 11. IP Registers

PX0HIPH (B7H)

Priority Bit = 1 assigns higher priority Priority Bit = 0 assigns lower priority

BIT SYMBOL FUNCTION

IPH.7 — Not implemented, reserved for future use. IPH.6 — Not implemented, reserved for future use. IPH.5 PT2H Timer 2 interrupt priority bit high. IPH.4 PSH Serial Port interrupt priority bit high. IPH.3 PT1H Timer 1 interrupt priority bit high. IPH.2 PX1H External interrupt 1 priority bit high. IPH.1 PT0H Timer 0 interrupt priority bit high. IPH.0 PX0H External interrupt 0 priority bit high.

SU01058

PT0HPX1HPT1HPSHPT2H——

01234567

Figure 12. IPH Registers

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1999 Oct 27

Reduced EMI Mode

The AO bit (AUXR.0) in the AUXR register when set disables the ALE output.

Reduced EMI Mode

AUXR (8EH)

765432 1 0 – – – – – – – AO

AUXR.0 AO Turns off ALE output.

Dual DPTR

The dual DPTR structure (see Figure 13) is a way by which the chip will specify the address of an external data memory location. There are two 16-bit DPTR registers that address the external memory, and a single bit called DPS = AUXR1/bit0 that allows the program code to switch between them.

•New Register Name: AUXR1#

•SFR Address: A2H

•Reset Value: xxxx00x0B

AUXR1 (A2H)

76543210 – – – – GF2 0 – DPS

Where:

DPS = AUXR1/bit0 = Switches between DPTR0 and DPTR1.

Select Reg DPS

DPTR0 0 DPTR1 1

The DPS bit status should be saved by software when switching between DPTR0 and DPTR1.

The GF0 bit is a general purpose user-defined flag. Note that bit 2 is not writable and is always read as a zero. This allows the DPS bit to be quickly toggled simply by executing an INC AUXR1 instruction without affecting the GF2 bit.

DPS

DPTR1 DPTR0

DPH

(83H)

DPL

(82H)

EXTERNAL

DATA

MEMORY

SU00745A

BIT0

AUXR1

Figure 13.

DPTR Instructions

The instructions that refer to DPTR refer to the data pointer that is currently selected using the AUXR1/bit 0 register. The six instructions that use the DPTR are as follows:

INC DPTR Increments the data pointer by 1 MOV DPTR, #data16 Loads the DPTR with a 16-bit constant MOV A, @ A+DPTR Move code byte relative to DPTR to ACC MOVX A, @ DPTR Move external RAM (16-bit address) to

ACC

MOVX @ DPTR , A Move ACC to external RAM (16-bit

address)

JMP @ A + DPTR Jump indirect relative to DPTR

The data pointer can be accessed on a byte-by-byte basis by specifying the low or high byte in an instruction which accesses the SFRs. See application note AN458 for more details.

Philips Semiconductors Product specification

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80C51 8-bit microcontroller family 4K/8K/16K/32K Flash

1999 Oct 27

ABSOLUTE MAXIMUM RATINGS

1, 2, 3

PARAMETER

RATING UNIT

Operating temperature under bias 0 to +70 or –40 to +85 °C Storage temperature range –65 to +150 °C Voltage on EA/VPP pin to V

0 to +13.0 V

Voltage on any other pin to V

–0.5 to +6.5 V Maximum IOL per I/O pin 15 mA Power dissipation (based on package heat transfer limitations, not device power consumption) 1.5 W

NOTES:

1. Stresses above those listed under Absolute Maximum Ratings may cause permanent damage to the device. This is a stress rating only and functional operation of the device at these or any conditions other than those described in the AC and DC Electrical Characteristics section of this specification is not implied.

2. This product includes circuitry specifically designed for the protection of its internal devices from the damaging effects of excessive static charge. Nonetheless, it is suggested that conventional precautions be taken to avoid applying greater than the rated maximum.

3. Parameters are valid over operating temperature range unless otherwise specified. All voltages are with respect to V

unless otherwise noted.

AC ELECTRICAL CHARACTERISTICS

amb

= 0°C to +70°C or –40°C to +85°C

SYMBOL

PARAMETER

CLOCK FREQUENCY

RANGE –f

UNIT

MIN MAX

1/t

CLCL

Oscillator frequency: U (33MHz) 0 33 MHz

Philips Semiconductors Product specification

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80C51 8-bit microcontroller family 4K/8K/16K/32K Flash

1999 Oct 27

DC ELECTRICAL CHARACTERISTICS

amb

= 0°C to +70°C or –40°C to +85°C; 5 V ±10%; VSS = 0 V

TEST

LIMITS

SYMBOL

PARAMETER

CONDITIONS

MIN TYP

MAX

UNIT

Input low voltage 4.5 V < VCC < 5.5 V –0.5 0.2 VCC–0.1 V

Input high voltage (ports 0, 1, 2, 3, EA) 0.2 VCC+0.9 VCC+0.5 V

IH1

Input high voltage, XTAL1, RST 0.7 V

VCC+0.5 V

Output low voltage, ports 1, 2, 3

VCC = 4.5 V

IOL = 1.6 mA

0.4 V

OL1

Output low voltage, port 0, ALE, PSEN

7, 8

VCC = 4.5 V

IOL = 3.2 mA

0.4 V

Output high voltage, ports 1, 2, 3

VCC = 4.5 V

IOH = –30 µA

VCC – 0.7 V

OH1

Output high voltage (port 0 in external bus mode), ALE9, PSEN

VCC = 4.5 V

IOH = –3.2 mA

VCC – 0.7 V

Logical 0 input current, ports 1, 2, 3 VIN = 0.4 V –1 –75 µA

Logical 1-to-0 transition current, ports 1, 2, 3

VIN = 2.0 V

See Note 4

–650 µA

Input leakage current, port 0 0.45 < VIN < VCC – 0.3 ±10 µA

Power supply current (see Figure 21): See Note 5

Active mode (see Note 5) Idle mode (see Note 5) Power-down mode or clock stopped (see Figure 25

amb

= 0°C to 70°C 3 100 µA

for conditions)

amb

= –40°C to +85°C 125 µA

RST

Internal reset pull-down resistor 40 225 kΩ

Pin capacitance10 (except EA) 15 pF

NOTES:

1. Typical ratings are not guaranteed. The values listed are at room temperature, 5 V.

2. Capacitive loading on ports 0 and 2 may cause spurious noise to be superimposed on the V

s of ALE and ports 1 and 3. The noise is due to external bus capacitance discharging into the port 0 and port 2 pins when these pins make 1-to-0 transitions during bus operations. In the worst cases (capacitive loading > 100pF), the noise pulse on the ALE pin may exceed 0.8V . In such cases, it may be desirable to qualify ALE with a Schmitt Trigger, or use an address latch with a Schmitt Trigger STROBE input. I

can exceed these conditions provided that no

single output sinks more than 5 mA and no more than two outputs exceed the test conditions.

3. Capacitive loading on ports 0 and 2 may cause the VOH on ALE and PSEN to momentarily fall below the VCC–0.7 specification when the address bits are stabilizing.

4. Pins of ports 1, 2 and 3 source a transition current when they are being externally driven from 1 to 0. The transition current reaches its maximum value when V

is approximately 2 V .

5. See Figures 22 through 25 for I

test conditions and Figure 21 for I

vs Freq.

Active mode: I

CC(MAX)

= (0.9 × FREQ. + 20)mA

Idle mode: I

CC(MAX)

= (0.37 × FREQ. +1.0)mA

6. This value applies to T

amb

= 0°C to +70°C.

7. Load capacitance for port 0, ALE, and PSEN

= 100pF, load capacitance for all other outputs = 80 pF .

8. Under steady state (non-transient) conditions, I

must be externally limited as follows:

Maximum I

per port pin: 15 mA (*NOTE: This is 85°C specification.)

Maximum I

per 8-bit port: 26 mA

Maximum total I

for all outputs: 71 mA

If I

exceeds the test condition, VOL may exceed the related specification. Pins are not guaranteed to sink current greater than the listed

test conditions.

9. ALE is tested to V

OH1

, except when ALE is off then VOH is the voltage specification.

10.Pin capacitance is characterized but not tested. Pin capacitance is less than 25 pF. Pin capacitance of ceramic package is less than 15 pF (except EA

is 25 pF).

Philips Semiconductors Product specification

89C51/89C52/89C54/89C58

80C51 8-bit microcontroller family 4K/8K/16K/32K Flash

1999 Oct 27

AC ELECTRICAL CHARACTERISTICS

amb

= 0°C to +70°C or –40°C to +85°C, VCC = 5 V ±10%, VSS = 0V

1, 2, 3

VARIABLE CLOCK

33MHz CLOCK

SYMBOL FIGURE PARAMETER MIN MAX MIN MAX UNIT

1/t

CLCL

14 Oscillator frequency

Speed versions: I;J;U (33 MHz)

3.5 33

MHz

LHLL

14 ALE pulse width 2t

CLCL

–40 21 ns

AVLL

14 Address valid to ALE low t

CLCL

–25 5 ns

LLAX

14 Address hold after ALE low t

CLCL

–25 5 ns

LLIV

14 ALE low to valid instruction in 4t

CLCL

–65 55 ns

LLPL

14 ALE low to PSEN low t

CLCL

–25 5 ns

PLPH

14 PSEN pulse width 3t

CLCL

–45 45 ns

PLIV

14 PSEN low to valid instruction in 3t

CLCL

–60 30 ns

PXIX

14 Input instruction hold after PSEN 0 0 ns

PXIZ

14 Input instruction float after PSEN t

CLCL

–25 5 ns

AVIV

14 Address to valid instruction in 5t

CLCL

–80 70 ns

PLAZ

14 PSEN low to address float 10 10 ns

Data Memory

RLRH

15, 16 RD pulse width 6t

CLCL

–100 82 ns

WLWH

15, 16 WR pulse width 6t

CLCL

–100 82 ns

RLDV

15, 16 RD low to valid data in 5t

CLCL

–90 60 ns

RHDX

15, 16 Data hold after RD 0 0 ns

RHDZ

15, 16 Data float after RD 2t

CLCL

–28 32 ns

LLDV

15, 16 ALE low to valid data in 8t

CLCL

–150 90 ns

AVDV

15, 16 Address to valid data in 9t

CLCL

–165 105 ns

LLWL

15, 16 ALE low to RD or WR low 3t

CLCL

–50 3t

CLCL

+50 40 140 ns

AVWL

15, 16 Address valid to WR low or RD low 4t

CLCL

–75 45 ns

QVWX

15, 16 Data valid to WR transition t

CLCL

–30 0 ns

WHQX

15, 16 Data hold after WR t

CLCL

–25 5 ns

QVWH

16 Data valid to WR high 7t

CLCL

–130 80 ns

RLAZ

15, 16 RD low to address float 0 0 ns

WHLH

15, 16 RD or WR high to ALE high t

CLCL

–25 t

CLCL

+25 5 55 ns

External Clock

CHCX

18 High time 17 t

CLCL–tCLCX

CLCX

18 Low time 17 t

CLCL–tCHCX

CLCH

18 Rise time 5 ns

CHCL

18 Fall time 5 ns

Shift Register

XLXL

17 Serial port clock cycle time 12t

CLCL

360 ns

QVXH

17 Output data setup to clock rising edge 10t

CLCL

–133 167 ns

XHQX

17 Output data hold after clock rising edge 2t

CLCL

–80 50 ns

XHDX

17 Input data hold after clock rising edge 0 0 ns

XHDV

17 Clock rising edge to input data valid 10t

CLCL

–133 167 ns

NOTES:

1. Parameters are valid over operating temperature range unless otherwise specified.

2. Load capacitance for port 0, ALE, and PSEN

= 100 pF, load capacitance for all other outputs = 80 pF .

3. Interfacing the microcontroller to devices with float times up to 45 ns is permitted. This limited bus contention will not cause damage to Port 0 drivers.

4. Parts are guaranteed to operate down to 0 Hz.

Philips Semiconductors Product specification

89C51/89C52/89C54/89C58

80C51 8-bit microcontroller family 4K/8K/16K/32K Flash

1999 Oct 27

EXPLANATION OF THE AC SYMBOLS

Each timing symbol has five characters. The first character is always ‘t’ (= time). The other characters, depending on their positions, indicate the name of a signal or the logical status of that signal. The designations are: A – Address C – Clock D – Input data H – Logic level high I – Instruction (program memory contents) L – Logic level low, or ALE

P – PSEN Q – Output data R–RD

signal t – Time V – Valid W– WR

signal X – No longer a valid logic level Z – Float Examples: t

AVLL

= Time for address valid to ALE low .

LLPL

=Time for ALE low to PSEN low.

PXIZ

ALE

PSEN

PORT 0

PORT 2

A0–A15 A8–A15

A0–A7 A0–A7

AVLL

PXIX

LLAX

INSTR IN

LHLL

PLPH

LLIV

PLAZ

LLPL

AVIV

SU00006

PLIV

Figure 14. External Program Memory Read Cycle

ALE

PSEN

PORT 0

PORT 2

A0–A7

FROM RI OR DPL

DATA IN A0–A7 FROM PCL INSTR IN

P2.0–P2.7 OR A8–A15 FROM DPF A0–A15 FROM PCH

WHLH

LLDV

LLWL

RLRH

LLAX

RLAZ

AVLL

RHDX

RHDZ

AVWL

AVDV

RLDV

SU00025

Figure 15. External Data Memory Read Cycle

Philips Semiconductors Product specification

89C51/89C52/89C54/89C58

80C51 8-bit microcontroller family 4K/8K/16K/32K Flash

1999 Oct 27

LLAX

ALE

PSEN

PORT 0

PORT 2

A0–A7

FROM RI OR DPL

DATA OUT A0–A7 FROM PCL INSTR IN

P2.0–P2.7 OR A8–A15 FROM DPF A0–A15 FROM PCH

WHLH

LLWL

WLWH

AVLL

AVWL

QVWX

WHQX

QVWH

SU00026

Figure 16. External Data Memory Write Cycle

012345678

INSTRUCTION

ALE

CLOCK

OUTPUT DATA

WRITE TO SBUF

INPUT DATA

CLEAR RI

VALID VALID VALID VALID VALID VALID VALID VALID

SET TI

SET RI

XLXL

QVXH

XHQX

XHDX

XHDV

SU00027

1230 4567

Figure 17. Shift Register Mode Timing

VCC–0.5

0.45V

0.7V

0.2VCC–0.1

CHCL

CLCL

CLCH

CLCX

CHCX

SU00009

Figure 18. External Clock Drive

Philips Semiconductors Product specification

89C51/89C52/89C54/89C58

80C51 8-bit microcontroller family 4K/8K/16K/32K Flash

1999 Oct 27

VCC–0.5

0.45V

0.2V

+0.9

0.2V

–0.1

NOTE: AC inputs during testing are driven at VCC –0.5 for a logic ‘1’ and 0.45V for a logic ‘0’. Timing measurements are made at VIH min for a logic ‘1’ and VIL max for a logic ‘0’.

SU00717

Figure 19. AC Testing Input/Output

LOAD

+0.1V

LOAD

–0.1V

+0.1V

NOTE:

TIMING

REFERENCE

POINTS

For timing purposes, a port is no longer floating when a 100mV change from load voltage occurs, and begins to float when a 100mV change from the loaded V

OH/VOL

level occurs. IOH/IOL ≥ ±20mA.

SU00718

Figure 20. Float Waveform

4 8 12 16 20 24 28 32 36

Frequency at XTAL1 (MHz)

(mA)

SU01056

Icc IDLE MODE (TYP.)

Icc MAX ACTIVE MODE (TYP.)

Icc MAX. ACTIVE MODE

Icc MAX. IDLE MODE

Figure 21. ICC vs. FREQ

Valid only within frequency specifications of the device under test

Philips Semiconductors Product specification

89C51/89C52/89C54/89C58

80C51 8-bit microcontroller family 4K/8K/16K/32K Flash

1999 Oct 27

RST

XTAL1

XTAL2

(NC)

CLOCK SIGNAL

SU00719

Figure 22. ICC Test Condition, Active Mode

All other pins are disconnected

P0 EA

RST

XTAL1

XTAL2

(NC)

CLOCK SIGNAL

SU00720

Figure 23. ICC Test Condition, Idle Mode

All other pins are disconnected

VCC–0.5

0.45V

0.7V

0.2VCC–0.1

CHCL

CLCL

CLCH

CLCX

CHCX

SU00009

Figure 24. Clock Signal Waveform for ICC Tests in Active and Idle Modes

CLCH

= t

CHCL

= 5ns

RST

XTAL1

XTAL2

(NC)

SU00016

Figure 25. ICC Test Condition, Power Down Mode All other pins are disconnected. V

= 2V to 5.5V

Philips Semiconductors Product specification

89C51/89C52/89C54/89C58

80C51 8-bit microcontroller family 4K/8K/16K/32K Flash

1999 Oct 27

Security

The security feature protects against software piracy and prevents the contents of the FLASH from being read. The Security Lock bits are located in FLASH. The 89C51/89C52/89C54/89C58 has 3 programmable security lock bits that will provide different levels of protection for the on-chip code and data (see Table 8). Unlike the ROM and OTP versions, the security lock bits are independent. LB3 includes the security protection of LB1.

Table 8.

SECURITY LOCK BITS

Level

PROTECTION DESCRIPTION

LB1

MOVC instructions executed from external program memory are disabled from fetching code bytes from

internal memory. LB2 Program verification is disabled LB3 External execution is disabled.

NOTE:

1. The security lock bits are independent.

Philips Semiconductors Product specification

89C51/89C52/89C54/89C58

80C51 8-bit microcontroller family 4K/8K/16K/32K Flash

1999 Oct 27

PLCC44: plastic leaded chip carrier; 44 leads SOT187-2

Philips Semiconductors Product specification

89C51/89C52/89C54/89C58

80C51 8-bit microcontroller family 4K/8K/16K/32K Flash

1999 Oct 27

DIP40: plastic dual in-line package; 40 leads (600 mil) SOT129-1

Philips Semiconductors Product specification

89C51/89C52/89C54/89C58

80C51 8-bit microcontroller family 4K/8K/16K/32K Flash

1999 Oct 27

QFP44: plastic quad flat package; 44 leads

Philips Semiconductors Product specification

89C51/89C52/89C54/89C58

80C51 8-bit microcontroller family 4K/8K/16K/32K Flash

1999 Oct 27

NOTES

Philips Semiconductors Product specification

89C51/89C52/89C54/89C58

80C51 8-bit microcontroller family 4K/8K/16K/32K Flash

1999 Oct 27

Definitions

Short-form specification — The data in a short-form specification is extracted from a full data sheet with the same type number and title. For

detailed information see the relevant data sheet or data handbook. Limiting values definition — Limiting values given are in accordance with the Absolute Maximum Rating System (IEC 134). Stress above one

or more of the limiting values may cause permanent damage to the device. These are stress ratings only and operation of the device at these or at any other conditions above those given in the Characteristics sections of the specification is not implied. Exposure to limiting values for extended periods may affect device reliability.

Application information — Applications that are described herein for any of these products are for illustrative purposes only. Philips Semiconductors make no representation or warranty that such applications will be suitable for the specified use without further testing or modification.

Disclaimers

Life support — These products are not designed for use in life support appliances, devices or systems where malfunction of these products can

reasonably be expected to result in personal injury . Philips Semiconductors customers using or selling these products for use in such applications do so at their own risk and agree to fully indemnify Philips Semiconductors for any damages resulting from such application.

Right to make changes — Philips Semiconductors reserves the right to make changes, without notice, in the products, including circuits, standard cells, and/or software, described or contained herein in order to improve design and/or performance. Philips Semiconductors assumes no responsibility or liability for the use of any of these products, conveys no license or title under any patent, copyright, or mask work right to these products, and makes no representations or warranties that these products are free from patent, copyright, or mask work right infringement, unless otherwise specified.

Philips Semiconductors 811 East Arques Avenue P.O. Box 3409 Sunnyvale, California 94088–3409 Telephone 800-234-7381

 Copyright Philips Electronics North America Corporation 1999

Date of release: 10-99

Document order number: 9397–750–06613

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Data sheet status

Objective specification

Preliminary specification

Product specification

Product status

Development

Qualification

Production

Definition

[1]

This data sheet contains the design target or goal specifications for product development. Specification may change in any manner without notice.

This data sheet contains preliminary data, and supplementary data will be published at a later date. Philips Semiconductors reserves the right to make changes at any time without notice in order to improve design and supply the best possible product.

This data sheet contains final specifications. Philips Semiconductors reserves the right to make changes at any time without notice in order to improve design and supply the best possible product.

Data sheet status

[1] Please consult the most recently issued datasheet before initiating or completing a design.

Datasheet P89C52UBPN, P89C54UBAA, P89C51UBPN, P89C51UBAA, P89C54NBPN Datasheet (Philips)

Specifications and Main Features

Frequently Asked Questions

User Manual