AT89S2051/4051 - Complete

Features
• Compatible with MCS®51 Products
• 2K/4K Bytes of In-System Programmable (ISP) Flash Program Memory
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– Serial Interface for Program Downloading
– Endurance: 10,000 Write/Erase Cycles
2.7V to 5.5V Operating Range
Fully Static Operation: 0 Hz to 24 MHz (x1 and x2 Modes)
Two-level Program Memory Lock
256 x 8-bit Internal RAM
15 Programmable I/O Lines
Two 16-bit Timer/Counters
Six Interrupt Sources
Programmable Serial UART Channel
Direct LED Drive Outputs
On-chip Analog Comparator with Selectable Interrupt
8-bit PWM (Pulse-width Modulation)
Low Power Idle and Power-down Modes
Brownout Reset
Enhanced UART Serial Port with Framing Error Detection and Automatic
Address Recognition
Internal Power-on Reset
Interrupt Recovery from Power-down Mode
Programmable and Fuseable x2 Clock Option
Four-level Enhanced Interrupt Controller
Power-off Flag
Flexible Programming (Byte and Page Modes)
– Page Mode: 32 Bytes/Page
User Serviceable Signature Page (32 Bytes)
8-bit
Microcontroller
with 2K/4K
Bytes Flash
AT89S2051
AT89S4051
1. Description
The AT89S2051/S4051 is a low-voltage, high-performance CMOS 8-bit microcontroller with 2K/4K bytes of In-System Programmable (ISP) Flash program memory.
The device is manufactured using Atmel’s high-density nonvolatile memory technology and is compatible with the industry-standard MCS-51 instruction set. By
combining a versatile 8-bit CPU with Flash on a monolithic chip, the Atmel
AT89S2051/S4051 is a powerful microcontroller which provides a highly-flexible and
cost-effective solution to many embedded control applications. Moreover, the
AT89S2051/S4051 is designed to be function compatible with the AT89C2051/C4051
devices, respectively.
The AT89S2051/S4051 provides the following standard features: 2K/4K bytes of
Flash, 256 bytes of RAM, 15 I/O lines, two 16-bit timer/counters, a six-vector, fourlevel interrupt architecture, a full duplex enhanced serial port, a precision analog
comparator, on-chip and clock circuitry. Hardware support for PWM with 8-bit resolution and 8-bit prescaler is available by reconfiguring the two on-chip timer/counters. In
addition, the AT89S2051/S4051 is designed with static logic for operation down to
zero frequency and supports two software-selectable power saving modes. The Idle
Mode stops the CPU while allowing the RAM, timer/counters, serial port and interrupt
system to continue functioning. The power-down mode saves the RAM contents
but freezes the disabling all other chip functions until the next external interrupt or
hardware reset.
3390E–MICRO–6/08
The on-board Flash program memory is accessible through the ISP serial interface. Holding
RST active forces the device into a serial programming interface and allows the program memory to be written to or read from, unless one or more lock bits have been activated.
2. Pin Configuration
2.1
20-lead PDIP/SOIC
RST/VPP
(RXD) P3.0
(TXD) P3.1
XTAL2
XTAL1
(INT0) P3.2
(INT1) P3.3
(T0) P3.4
(T1) P3.5
GND
1
2
3
4
5
6
7
8
9
10
20
19
18
17
16
15
14
13
12
11
VCC
P1.7 (SCK)
P1.6 (MISO)
P1.5 (MOSI)
P1.4
P1.3
P1.2
P1.1 (AIN1)
P1.0 (AIN0)
P3.7
3. Block Diagram
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AT89S2051/S4051
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AT89S2051/S4051
4. Pin Description
4.1
VCC
Supply voltage.
4.2
GND
Ground.
4.3
Port 1
Port 1 is an 8-bit bi-directional I/O port. Port pins P1.2 to P1.7 provide internal pull-ups. P1.0 and
P1.1 require external pull-ups. P1.0 and P1.1 also serve as the positive input (AIN0) and the
negative input (AIN1), respectively, of the on-chip precision analog comparator. The Port 1 output buffers can sink 20 mA and can drive LED displays directly. When 1s are written to Port 1
pins, they can be used as inputs. When pins P1.2 to P1.7 are used as inputs and are externally
pulled low, they will source current (IIL) because of the internal pull-ups.
Port 1 also receives code data during Flash programming and verification.
4.4
Port Pin
Alternate Functions
P1.5
MOSI (Master data output, slave data input pin for ISP channel)
P1.6
MISO (Master data input, slave data output pin for ISP channel)
P1.7
SCK (Master clock output, slave clock input pin for ISP channel)
Port 3
Port 3 pins P3.0 to P3.5, P3.7 are seven bi-directional I/O pins with internal pull-ups.
P3.6 is hard-wired as an input to the output of the on-chip comparator and is not accessible as a
general-purpose I/O pin. The Port 3 output buffers can sink 20 mA. When 1s are written to Port
3 pins they 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 (IIL) because of the pull-ups.
Port 3 also serves the functions of various special features of the AT89S2051/S4051 as listed
below:
Port Pin
Alternate Functions
P3.0
RXD (serial input port)
P3.1
TXD (serial output port)
P3.2
INT0 (external interrupt 0)
P3.3
INT1 (external interrupt 1)
P3.4
T0 (timer 0 external input)
P3.5
T1 (timer 1 external input)/ PWM output
Port 3 also receives some control signals for Flash programming and verification.
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3390E–MICRO–6/08
4.5
RST
Reset input. Holding the RST pin high for two machine cycles while the is running resets the
device.
Each machine cycle takes 6 or clock cycles.
4.6
XTAL1
Input to the inverting amplifier and input to the internal clock operating circuit.
4.7
XTAL2
Output from the inverting amplifier.
5.
Characteristics
XTAL1 and XTAL2 are the input and output, respectively, of an inverting amplifier which can be
configured for use as an on-chip , as shown in Figure 5-1. Either a quartz crystal or ceramic resonator may be used. To drive the device from an external clock source, XTAL2 should be left
unconnected while XTAL1 is driven as shown in Figure 5-2. There are no requirements on the
duty cycle of the external clock signal, since the input to the internal clocking circuitry is through
a divide-by-two flip-flop, but minimum and maximum voltage high and low time specifications
must be observed.
Figure 5-1.
Note:
C1, C2 = 5 pF ± 5 pF for Crystals
= 5 pF ± 5 pF for Ceramic Resonators
Figure 5-2.
4
Connections
External Clock Drive Configuration
AT89S2051/S4051
3390E–MICRO–6/08
AT89S2051/S4051
6. X2 Mode Description
The clock for the entire circuit and peripherals is normally divided by 2 before being used by the
CPU core and peripherals. This allows any cyclic ratio (duty cycle) to be accepted on XTAL1
input. In X2 mode this divider is bypassed. Figure 6-1 shows the clock generation block diagram.
Figure 6-1.
Clock Generation Block Diagram
X2 Mode
÷2
XTAL1
FXTAL
(XTAL1)/2
FOSC
State Machine: 6 Clock Cycles
CPU Control
7. Special Function Registers
A map of the on-chip memory area called the Special Function Register (SFR) space is shown in
Table 7-1.
Note that not all of the addresses are occupied, and unoccupied addresses may not be implemented on the chip. Read accesses to these addresses will in general return random data, and
write accesses will have an indeterminate effect.
User software should not write 1s to these unlisted locations, since they may be used in future
products to invoke new features. In that case, the reset or inactive values of the new bits will
always be 0.
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3390E–MICRO–6/08
Table 7-1.
AT89S2051/S4051 SFR Map and Reset Values
0F8H
0F0H
0FFH
B
00000000
0F7H
0E8H
0E0H
0EFH
ACC
00000000
0E7H
0D8H
0D0H
0DFH
PSW
00000000
0D7H
0C8H
0CFH
0C0H
0C7H
0B8H
IP
X0X00000
0B0H
P3
11111111
0A8H
IE
00X00000
SADEN
00000000
0BFH
IPH
X0X00000
SADDR
00000000
0AFH
0A0H
6
0A7H
98H
SCON
00000000
90H
P1
11111111
88H
TCON
00000000
80H
0B7H
SBUF
XXXXXXXX
9FH
TMOD
00000000
TL0
00000000
TL1
00000000
SP
00000111
DPL
00000000
DPH
00000000
TH0
00000000
TH1
00000000
ACSR
XXX00000
97H
CLKREG
XXXXXX0X
8FH
PCON
000X0000
87H
AT89S2051/S4051
3390E–MICRO–6/08
AT89S2051/S4051
8. Restrictions on Certain Instructions
The AT89S2051/S4051 is an economical and cost-effective member of Atmel’s family of microcontrollers. It contains 2K/4K bytes of Flash program memory. It is fully compatible with the
MCS-51 architecture, and can be programmed using the MCS-51 instruction set. However,
there are a few considerations one must keep in mind when utilizing certain instructions to program this device.
All the instructions related to jumping or branching should be restricted such that the destination
address falls within the physical program memory space of the device, which is 2K/4K for the
AT89S2051/S4051. This should be the responsibility of the software programmer. For example,
LJMP 7E0H would be a valid instruction for the AT89S2051 (with 2K of memory), whereas LJMP
900H would not.
8.1
Branching Instructions
LCALL, LJMP, ACALL, AJMP, SJMP, JMP @A+DPTR. These unconditional branching
instructions will execute correctly as long as the programmer keeps in mind that the destination
branching address must fall within the physical boundaries of the program memory size (locations 00H to 7FFH/FFFH for the AT89S2051/S4051). Violating the physical space limits may
cause unknown program behavior.
CJNE [...], DJNZ [...], JB, JNB, JC, JNC, JBC, JZ, JNZ. With these conditional branching
instructions, the same rule above applies. Again, violating the memory boundaries may cause
erratic execution.
For applications involving interrupts, the normal interrupt service routine address locations of the
80C51 family architecture have been preserved.
8.2
MOVX-related Instructions, Data Memory
The AT89S2051/S4051 contains 256 bytes of internal data memory. External DATA memory
access is not supported in this device, nor is external PROGRAM memory execution. Therefore,
no MOVX [...] instructions should be included in the program.
A typical 80C51 assembler will still assemble instructions, even if they are written in violation of
the restrictions mentioned above. It is the responsibility of the user to know the physical features
and limitations of the device being used and adjust the instructions used accordingly.
9. Program Memory Lock Bits
On the chip are two lock bits which can be left unprogrammed (U) or can be programmed (P) to
obtain the additional features listed in Table 9-1:
Table 9-1.
Lock Bit Protection Modes(1)
Program Lock Bits
Note:
LB1
LB2
Protection Type
1
U
U
No program lock features.
2
P
U
Further programming of the Flash is disabled.
3
P
P
Same as mode 2, also verify is disabled.
1. The Lock Bits can only be erased with the Chip Erase operation.
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3390E–MICRO–6/08
10. Reset
During reset, all I/O Registers are set to their initial values, the port pins are weakly pulled to
VCC, and the program starts execution from the Reset Vector, 0000H. The AT89S2051/S4051
has three sources of reset: power-on reset, brown-out reset, and external reset.
10.1
Power-On Reset
A Power-On Reset (POR) is generated by an on-chip detection circuit. The detection level is
nominally 1.4V. The POR is activated whenever VCC is below the detection level. The POR circuit can be used to trigger the start-up reset or to detect a supply voltage failure in devices
without a brown-out detector. The POR circuit ensures that the device is reset from power-on.
When VCC reaches the Power-on Reset threshold voltage, the Pierce Oscillator is enabled (if the
XTAL Oscillator Bypass fuse is OFF). Only after VCC has also reached the BOD (brown-out
detection) level (see Section 10.2 ”Brown-out Reset”), the BOD delay counter starts measuring a
2-ms delay after which the Internal Reset is deasserted and the microcontroller starts executing.
The built-in 2-ms delay allows the VCC voltage to reach the minimum 2.7V level before executing, thus guaranteeing the maximum operating clock frequency. The POR signal is activated
again, without any delay, when VCC falls below the POR threshold level. A Power-On Reset (i.e.
a cold reset) will set the POF flag in PCON. Refer to Figure 10-1 for details on the POR/BOD
behavior.
Figure 10-1. Power-up and Brown-out Detection Sequence
VCC
Min VCC Level 2.7V
BOD Level 2.3V
POR Level 1.4V
t
POR
t
2.4V
XTAL1
1.2V
t
BOD
t
Internal
RESET
tPOR
(2 ms)
tPOR
(2 ms)
tPOR
(2 ms)
t
0
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AT89S2051/S4051
3390E–MICRO–6/08
AT89S2051/S4051
10.2
Brown-out Reset
The AT89S2051/S4051 has an on-chip Brown-out Detection (BOD) circuit for monitoring the VCC
level during operation by comparing it to a fixed trigger level. The trigger level for the BOD is
nominally 2.0V. The purpose of the BOD is to ensure that if VCC fails or dips while executing at
speed, the system will gracefully enter reset without the possibility of errors induced by incorrect
execution. When VCC decreases to a value below the trigger level, the Brown-out Reset is immediately activated. When VCC increases above the trigger level, the BOD delay counter starts the
microcontroller after the timeout period has expired in approximately 2 ms.
10.3
External Reset
The RST pin functions as an active-high reset input. The pin must be held high for at least two
machine cycles to trigger the internal reset. RST also serves as the In-System Programming
(ISP) enable input. ISP mode is enabled when the external reset pin is held high and the ISP
Enable fuse is set.
11. Clock Register
.
Table 11-1.
CLKREG – Clock Register
CLKREG = 8FH
Reset Value = XXXX XX0XB
Not Bit Addressable
Bit
–
–
–
–
–
–
PWDEX
X2
7
6
5
4
3
2
1
0
Symbol
Function
PWDEX
Power-down Exit Mode. When PWDEX = 1, wake up from Power-down is externally controlled. When PWDEX = 0, wake
up from Power-down is internally timed.
X2
When X2 = 0, the frequency (at XTAL1 pin) is internally divided by 2 before it is used as the device system frequency.
When X2 = 1, the divide by 2 is no longer used and the XTAL1 frequency becomes the device system frequency. This
enables the user to use a 6 MHz crystal instead of a 12 MHz crystal in order to reduce EMI. The X2 bit is initialized on
power-up with the value of the X2 user fuse and may be changed at runtime by software.
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3390E–MICRO–6/08
12. Power Saving Modes
The AT89S2051/S4051 supports two power-reducing modes: Idle and Power-down. These
modes are accessed through the PCON register.
12.1
Idle Mode
Setting the IDL bit in PCON enters idle mode. Idle mode halts the internal CPU clock. The CPU
state is preserved in its entirety, including the RAM, stack pointer, program counter, program
status word, and accumulator. The Port pins hold the logical states they had at the time that Idle
was activated. Idle mode leaves the peripherals running in order to allow them to wake up the
CPU when an interrupt is generated. Timer 0, Timer 1, and the UART will continue to function
during Idle mode. The analog comparator is disabled during Idle. Any enabled interrupt source
or reset may terminate Idle mode. When exiting Idle mode with an interrupt, the interrupt will
immediately be serviced, and following RETI, the next instruction to be executed will be the one
following the instruction that put the device into Idle.
P1.0 and P1.1 should be set to “0” if no external pull-ups are used, or set to “1” if external pullups are used.
12.2
Power-down Mode
Setting the PD bit in PCON enters Power-down mode. Power-down mode stops the and powers
down the Flash memory in order to minimize power consumption. Only the power-on circuitry
will continue to draw power during Power-down. During Power-down the power supply voltage
may be reduced to the RAM keep-alive voltage. The RAM contents will be retained; however,
the SFR contents are not guaranteed once VCC has been reduced. Power-down may be exited
by external reset, power-on reset, or certain interrupts.
The user should not attempt to enter (or re-enter) the power-down mode for a minimum of 4 µs
until after one of the following conditions has occurred: Start of code execution (after any type of
reset), or Exit from power-down mode.
12.3
Interrupt Recovery from Power-down
Two external interrupts may be configured to terminate Power-down mode. External interrupts
INT0 (P3.2) and INT1 (P3.3) may be used to exit Power-down. To wake up by external interrupt
INT0 or INT1, the interrupt must be enabled and configured for level-sensitive operation.
When terminating Power-down by an interrupt, two different wake up modes are available.
When PWDEX in CLKREG.2 is zero, the wake up period is internally timed. At the falling edge
on the interrupt pin, Power-down is exited, the is restarted, and an internal timer begins counting. The internal clock will not be allowed to propagate and the CPU will not resume execution
until after the timer has counted for nominally 2 ms. After the timeout period the interrupt service
routine will begin. To prevent the interrupt from re-triggering, the ISR should disable the interrupt
before returning. The interrupt pin should be held low until the device has timed out and begun
executing.
When PWDEX = 1 the wakeup period is controlled externally by the interrupt. Again, at the falling edge on the interrupt pin, Power-down is exited and the is restarted. However, the internal
clock will not propagate and CPU will not resume execution until the rising edge of the interrupt
pin. After the rising edge on the pin, the interrupt service routine will begin. The interrupt should
be held low long enough for the to stabilize.
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AT89S2051/S4051
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AT89S2051/S4051
12.4
Reset Recovery from Power-down
Wakeup from Power-down through an external reset is similar to the interrupt with PWDEX = 0.
At the rising edge of RST, Power-down is exited, the is restarted, and an internal timer begins
counting. The internal clock will not be allowed to propagate to the CPU until after the timer has
counted for nominally 2 ms. The RST pin must be held high for longer than the timeout period to
ensure that the device is reset properly. The device will begin executing once RST is brought
low.
It should be noted that when idle 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 to a
port pin 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.
P1.0 and P1.1 should be set to “0” if no external pull-ups are used, or set to “1” if external pullups are used.
.
Table 12-1.
PCON – Power Control Register
PCON = 87H
Reset Value = 000X 0000B
Not Bit Addressable
Bit
SMOD1
SMOD0
PWMEN
POF
GF1
GF0
PD
IDL
7
6
5
4
3
2
1
0
Symbol
Function
SMOD1
Double Baud Rate bit. Doubles the baud rate of the UART in modes 1, 2, or 3.
SMOD0
Frame Error Select. When SMOD0 = 0, SCON.7 is SM0. When SMOD0 = 1, SCON.7 is FE. Note that FE will be set after
a frame error regardless of the state of SMOD0.
PWMEN
Pulse Width Modulation Enable. When PWMEN = 1, Timer 0 and Timer 1 are configured as an 8-bit PWM counter with
8-bit auto-reload prescaler. The PWM outputs on T1 (P3.5).
POF
Power Off Flag. POF is set to “1” during power up (i.e. cold reset). It can be set or reset under software control and is not
affected by RST or BOD (i.e. warm resets).
GF1, GF0
General-purpose Flags
PD
Power Down bit. Setting this bit activates power down operation.
IDL
Idle Mode bit. Setting this bit activates idle mode operation
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3390E–MICRO–6/08
13. Interrupts
The AT89S2051/S4051 provides 6 interrupt sources: two external interrupts, two timer interrupts, a serial port interrupt, and an analog comparator interrupt. These interrupts and the
system reset each have a separate program vector at the start of the program memory space.
Each interrupt source can be individually enabled or disabled by setting or clearing a bit in the
interrupt enable register IE. The IE register also contains a global disable bit, EA, which disables
all interrupts.
Each interrupt source can be individually programmed to one of four priority levels by setting or
clearing bits in the interrupt priority registers IP and IPH. An interrupt service routine in progress
can be interrupted by a higher priority interrupt, but not by another interrupt of the same or lower
priority. The highest priority interrupt cannot be interrupted by any other interrupt source. If two
requests of different priority levels are pending at the end of an instruction, the request of higher
priority level is serviced. If requests of the same priority level are pending at the end of an
instruction, an internal polling sequence determines which request is serviced. The polling
sequence is based on the vector address; an interrupt with a lower vector address has higher
priority than an interrupt with a higher vector address. Note that the polling sequence is only
used to resolve pending requests of the same priority level.
The External Interrupts INT0 and INT1 can each be either level-activated or transition-activated,
depending on bits IT0 and IT1 in Register TCON. The flags that actually generate these interrupts are the IE0 and IE1 bits in TCON. When the service routine is vectored to, hardware clears
the flag that generated an external interrupt only if the interrupt was transition-activated. If the
interrupt was level activated, then the external requesting source (rather than the on-chip hardware) controls the request flag.
The Timer 0 and Timer 1 Interrupts are generated by TF0 and TF1, which are set by a rollover in
their respective Timer/Counter registers (except for Timer 0 in Mode 3). When a timer interrupt is
generated, the on-chip hardware clears the flag that generated it when the service routine is
vectored to.
The Serial Port Interrupt is generated by the logical OR of RI and TI in SCON. Neither of these
flags is cleared by hardware when the service routine is vectored to. In fact, the service routine
normally must determine whether RI or TI generated the interrupt, and the bit must be cleared in
software.
The CF bit in ACSR generates the Comparator Interrupt. The flag is not cleared by hardware
when the service routine is vectored to and must be cleared by software.
Most of the bits that generate interrupts can be set or cleared by software, with the same result
as though they had been set or cleared by hardware. That is, interrupts can be generated and
pending interrupts can be canceled in software.
12
Interrupt
Source
Vector Address
System Reset
RST or POR or BOD
0000H
External Interrupt 0
IE0
0003H
Timer 0 Overflow
TF0
000BH
External Interrupt 1
IE1
0013H
Timer 1 Overflow
TF1
001BH
Serial Port
RI or TI
0023H
Analog Comparator
CF
0033H
AT89S2051/S4051
3390E–MICRO–6/08
AT89S2051/S4051
14. Interrupt Registers
Table 14-1.
IE – Interrupt Enable Register
IE = A8H
Reset Value = 00X0 0000B
Bit Addressable
Bit
EA
EC
–
ES
ET1
EX1
ET0
EX0
7
6
5
4
3
2
1
0
Symbol
Function
EA
Global enable/disable. All interrupts are disabled when EA = 0. When EA = 1, each interrupt source is enabled/disabled
by setting/clearing its own enable bit.
EC
Comparator Interrupt Enable
ES
Serial Port Interrupt Enable
ET1
Timer 1 Interrupt Enable
EX1
External Interrupt 1 Enable
ET0
Timer 0 Interrupt Enable
EX0
External Interrupt 0 Enable
.
Table 14-2.
IP – Interrupt Priority Register
IP = B8H
Reset Value = X0X0 0000B
Bit Addressable
Bit
–
PC
–
PS
PT1
PX1
PT0
PX0
7
6
5
4
3
2
1
0
Symbol
Function
PC
Comparator Interrupt Priority Low
PS
Serial Port Interrupt Priority Low
PT1
Timer 1 Interrupt Priority Low
PX1
External Interrupt 1 Priority Low
PT0
Timer 0 Interrupt Priority Low
PX0
External Interrupt 0 Priority Low
.
Table 14-3.
IPH – Interrupt Priority High Register
IPH = B7H
Reset Value = X0X0 0000B
Not Bit Addressable
Bit
–
PCH
–
PSH
PT1H
PX1H
PT0H
PX0H
7
6
5
4
3
2
1
0
Symbol
Function
PCH
Comparator Interrupt Priority High
PSH
Serial Port Interrupt Priority High
PT1H
Timer 1 Interrupt Priority High
PX1H
External Interrupt 1 Priority High
PT0H
Timer 0 Interrupt Priority High
PX0H
External Interrupt 0 Priority High
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3390E–MICRO–6/08
15. Timer/Counters
The AT89S2051/S4051 have two 16-bit Timer/Counters: Timer 0 and Timer 1. The Timer/Counters are identical to those in the AT89C2051/C4051. For more detailed information on the
Timer/Counter operation, please click on the document link below:
http://www.atmel.com/dyn/resources/prod_documents/DOC4316.PDF
16. Pulse Width Modulation
Timer 0 and Timer 1 may be configured as an 8-bit pulse width modulator by setting the PWMEN
bit in PCON. The generated waveform is output on the Timer 1 input pin, T1. In PWM mode
Timer 0 acts as an 8-bit prescaler to select the PWM timebase. Timer 0 is forced into Mode 2 (8bit auto-reload) by PWMEN and the value in TH0 will determine the clock division from 0 (FFh)
to 256 (00h). Timer 1 acts as the 8-bit PWM counter. TL1 counts once on every overflow from
TL0. TH1 stores the 8-bit pulse width value. On the FFh-->00h overflow of TL1, the PWM output
is set high. When the count in TL1 matches the value in TH1, the PWM output is set low. Therefore, the output pulse width is proportional to the value in TH1. To prevent glitches, writes to TH1
only take effect on the FFh-->00h overflow of TL1. However, a read from TH1 will read the new
value at any time after a write to TH1. See Figure 16-1 for PWM waveform example.
Figure 16-1. Pulse Width Modulation (PWM) Output Waveform
Counter Value (TL1)
Compare Value (TH1)
PWM Output (T1)
Figure 16-2. Timer 0/1 Pulse Width Modulation Mode
TH1
TH0
OCR
P3.5
=?
PWM
OSC
÷12
TL0
TL1
TL0 counts once every machine cycle (1 machine cycle = 12 clocks in X1 mode) and TH0 is the
reload value for when TL0 overflows. Every time TL0 overflows TL1 increments by one, with TL0
overflowing after counting 256 minus TH0 machine cycles.
To calculate the pulse width for the PWM output on pin T1, users should use the following
formula:
TH1 * (256 - TH0) * (1/clock_freq) * 12 = Pulse Width
14
AT89S2051/S4051
3390E–MICRO–6/08
AT89S2051/S4051
TL1 will always count from 00h to FFh. The output on the Timer 1 (T1) pin will be high from when
TL1 equals 00h until TL1 equals TH1 (see Figure 16-3). TH1 does not act as the reload value for
TL1 on overflow. Instead, TH1 is used strictly as a compare value (see Figure 16-2).
Figure 16-3. Example of a PWM Output
TL1 Count 00
01
10 . . . TH1
. . . FF
00
...
T1
17. UART
The UART in the AT89S2051/S4051 operates the same way as the UART in the
AT89C2051/C4051. For more detailed information on the UART operation, please click on the
document link below:
http://www.atmel.com/dyn/resources/prod_documents/DOC4316.PDF
17.1
Enhanced UART
In addition to all of its usual modes, the UART can perform framing error detection 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). 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.
17.2
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.
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 be used and which bits are “don’t care”. The SADEN mask can
15
3390E–MICRO–6/08
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
Slave 1
= 1100 00X0
SADDR = 1100 0000
SADEN = 1111 1110
Given
= 1100 000X
In the previous 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
Slave 1
= 1100 0XX0
SADDR = 1110 0000
SADEN = 1111 1010
Given
Slave 2
= 1110 0X0X
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 0110. 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 loaded 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.
16
AT89S2051/S4051
3390E–MICRO–6/08
AT89S2051/S4051
Table 17-1.
SCON – Serial Port Control Register
SCON Address = 98H
Reset Value = 0000 0000B
Bit Addressable
Bit
SM0/FE
SM1
SM2
REN
TB8
RB8
TI
RI
7
6
5
4
3
2
1
0
(SMOD = 0/1)(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. FE will be set
regardless of the state of SMOD.
SM0
Serial Port Mode Bit 0, (SMOD must = 0 to access bit SM0)
Serial Port Mode Bit 1
SM1
SM0
SM1
Mode
Description
Baud Rate(2)
0
0
0
shift register
fosc/12
0
1
1
8-bit UART
variable
1
0
2
9-bit UART
fosc/64 or fosc/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
TI
RI
Notes:
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.
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.
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.
1. SMOD is located at PCON.7.
2. fosc = frequency.
17
3390E–MICRO–6/08
18. Analog Comparator
A single analog comparator is provided in the AT89S2051/S4051. The comparator operation is
such that the output is a logical “1” when the positive input AIN0 (P1.0]) is greater than the negative input AIN1 (P1.1). Otherwise the output is a zero. Setting the CEN bit in ACSR enables the
comparator. When the comparator is first enabled, the comparator output and interrupt flag are
not guaranteed to be stable for 10 microseconds. The corresponding comparator interrupt
should not be enabled during that time, and the comparator interrupt flag must be cleared before
the interrupt is enabled in order to prevent an immediate interrupt service.
The comparator may be configured to cause an interrupt under a variety of output value conditions by setting the CM bits in ACSR. The comparator interrupt flag CF in ACSR is set whenever
the comparator output matches the condition specified by CM. The flag may be polled by software or may be used to generate an interrupt and must be cleared by software. The analog
comparator is always disabled during Idle or Power-down modes.
19. Comparator Interrupt with Debouncing
The comparator output is sampled at every State 4 (S4) of every machine cycle. The conditions
on the analog inputs may be such that the comparator output will toggle excessively. This is
especially true if applying slow moving analog inputs. Three debouncing modes are provided to
filter out this noise. In debouncing mode, the comparator uses Timer 1 to modulate its sampling
time. When a relevant transition occurs, the comparator waits until two Timer 1 overflows have
occurred before resampling the output. If the new sample agrees with the expected value, CF is
set. Otherwise, the event is ignored. The filter may be tuned by adjusting the timeout period of
Timer 1. Because Timer 1 is free running, the debouncer must wait for two overflows to guarantee that the sampling delay is at least 1 timeout period. Therefore after the initial edge event, the
interrupt may occur between 1 and 2 timeout periods later. See Figure 19-1.
Figure 19-1. Example of Negative Edge Comparator Interrupt with Debouncing
Comparator Out
Timer 1 Overflow
CF
START
COMPARE
START
18
COMPARE
AT89S2051/S4051
3390E–MICRO–6/08
AT89S2051/S4051
20. Analog Comparator Register
.
Table 20-1.
ACSR – Analog Comparator Control & Status Register
ACSR = 97H
Reset Value = XXX0 0000B
Not Bit Addressable
Bit
–
–
–
CF
CEN
CM2
CM1
CM0
7
6
5
4
3
2
1
0
Symbol
Function
CF
Comparator Interrupt Flag. Set when the comparator output meets the conditions specified by the CM [2:0] bits and CEN
is set. The flag must be cleared by software. The interrupt may be enabled/disabled by setting/clearing bit 6 of IE.
CEN
Comparator Enable. Set this bit to enable the comparator. Clearing this bit will force the comparator output low and
prevent further events from setting CF.
CM [2:0]
Comparator Interrupt Mode
2 1 0
Interrupt Mode
--- ---- -----------------------------------------0 0 0
Negative (Low) level
0 0 1
Positive edge
0 1 0
Toggle with debounce
0 1 1
Positive edge with debounce
1 0 0
Negative edge
1 0 1
Toggle
1 1 0
Negative edge with debounce
1 1 1
Positive (High) level
19
3390E–MICRO–6/08
21. Parallel Programming Specification
Atmel’s AT89S2051/S4051 offers 2K/4K bytes of In-System Programmable Flash code memory.
In addition, the device contains a 32-byte User Signature Row and a 32-byte read-only Atmel
Signature Row.
Table 21-1.
Memory Organization
Device #
Page Size
# Pages
Address Range
Page Range
AT89S2051
32 bytes
64
0000H - 07FFH
00H - 3FH
AT89S4051
32 bytes
128
0000H - 0FFFH
00H - 7FH
Figure 21-1. Flash Parallel Programming Device Connections
AT89S2051/S4051
2.7V to 5.5V
VCC
RDY/BSY (1)
P3.1
PROG
P3.2
TestCode
P3.7-3
INC
XTAL1
P1.7 - P1.0
RST
DATA IN/OUT
VPP
GND
Note:
20
1. Sampling of pin P3.1 (RDY/BSY) is optional. In Parallel Mode, P3.1 will be pulled low while the
device is busy. However, it requires an external passive pull-up to VCC. Also, note that P3.6
does not exist, so TestCode connects to P3.7, P3.5, P3.4, and P3.3.
AT89S2051/S4051
3390E–MICRO–6/08
AT89S2051/S4051
Table 21-2.
Parallel Programming Mode Command Summary
Test Control
P3.2
(5)
Chip Erase
Page Read(3)
Page Write
(3)(4)(6)(7)
(3)(8)(10)
Page Read
Write Fuse/Lock Bit
P3.5
P3.7
P1.7-0
L
H
L
L
L
XX
H
12V
0.1 µs
H
L
H
H
DIN
Code Memory
1.0 µs
12V
0.1 µs
L
H
H
H
DIN
Code Memory
H
12V
0.1 µs
L
L
H
H
DOUT
Sig. Row
1.0 µs
12V
0.1 µs
L
L
L
L
DIN
Sig. Row
H
12V
0.1 µs
L
L
L
H
DOUT
1.0 µs
12V
L
H
H
H
H
DIN
H
12V
L
H
H
L
L
DOUT
(5)(9)
Read Fuse/Lock Bit(9)
1.
2.
3.
4.
P3.4
12V
Load X-Address
Page Write
P3.3
1.0 µs
(2)
(3)(4)(6)
Data I/O
INC
RST(1)
Mode
Notes:
Test Selects
The internal Y-address counter is reset to 00H on the rising/falling edge of RST.
A positive pulse on XTAL1 loads the address data on Port P1 into the X-address (page) register and resets the Y-address.
A positive pulse on XTAL1 advances the Y-address counter.
A low pulse on P3.2 loads data from Port P1 for the current address. If another P3.2 low pulse does not arrive within 150 µs,
programming starts.
Internally timed for 4 ms.
Internally timed for 2 ms.
00H must be loaded into the X-address before executing this command.
Will read User Signature if X-address is 00H, will read Atmel Signature if X-address is 01H.
5.
6.
7.
8.
9. Fuse/Lock Bit Definitions:
Bit 7
XTAL Osc Bypass
Enable = 0/Disable = 1
Bit 6
User Row Programming
Enable = 0/Disable = 1
Bit 5
x2 Clock
Enable = 0/Disable = 1
Bit 4
Serial Programming
Enable = 0/Disable = 1
Bit 1
Lock Bit 2
Locked = 0/Unlocked = 1
Bit 0
Lock Bit 1
Locked = 0/Unlocked = 1
10. Atmel Signature Bytes:
AT89S2051:
Address
00H = 1EH
01H = 23H
02H = FFH
AT89S4051:
Address
00H = 1EH
01H = 43H
02H = FFH
21
3390E–MICRO–6/08
22. Power-up Sequence
Execute the following sequence to power-up the device before programming.
1. Apply power between VCC and GND pins.
2. After VCC has settled, wait 10 µs and bring RST to “H”.
3. Wait 4 ms for the internal Power-on Reset to timeout.
4. Bring P3.2 to “H” and drive P3.7, P3.5, P3.4, and P3.3 to known values, then wait
10 µs.
5. Raise RST/VPP to 12V to enable the parallel programming modes.
6. After VPP has settled, wait an additional 10 µs before programming.
Figure 22-1. Power-up Operation
VCC
RST/VPP
P3.2
XTAL1
P3.3 - P3.7
High Z
P1.0 - P1.7
High Z
RDY/BSY
High Z
23. Power-down Sequence
Execute the following sequence to power-down the device after programming.
1. Tri-state Port P1.
2. Bring RST/VPP down from 12V to VCC and wait 10 µs.
3. Bring XTAL and P3.2 to “L” and tri-state P3.7, P3.5, P3.4, and P3.3.
4. Bring RST to “L” and wait 10 µs.
5. Power off VCC.
Figure 23-1. Power-down Operation
VCC
RST/VPP
P3.2
XTAL1
22
P3.3 - P3.7
High Z
P1.0 - P1.7
High Z
RDY/BSY
High Z
AT89S2051/S4051
3390E–MICRO–6/08
AT89S2051/S4051
24. Chip Erase
Function:
1. FFH programmed to every address location.
2. FFH programmed to User Signature Row if User Row Fuse bit is enabled.
3. Lockbit1 and Lockbit2 programmed to “unlock” state.
Usage:
1. Apply “0001” TestCode to P3.7, P3.5, P3.4, P3.3.
2. Pulse P3.2 low for 1 µs.
3. Wait 4 ms, monitor P3.1, or poll data.
Note:
This and the following waveforms are not to scale.
Figure 24-1. Chip Erase Sequence
P3.2
XTAL1
P3.3 - P3.7
P1.0 - P1.7
0001
High Z
RDY/BSY
25. Load X-Address
Function:
1. Loads the X-Address register with data on Port P1. The loaded address will select the
page for subsequent write/read commands. The X-Address is equivalent to bits [11:5]
of the full byte address.
2. Resets the Y-Address counter to 00H. The Y-Address is equivalent to bits [4:0] of the
full byte address and selects a byte within a page.
Usage:
1. Apply “1101” TestCode to P3.7, P3.5, P3.4, P3.3.
2. Drive Port P1 with 8-bit X-address data.
3. Pulse XTAL1 high for at least 100 ns. The address is latched on the falling edge of
XTAL1.
Figure 25-1. Load X-Address Sequence
P3.2
XTAL1
P3.3 - P3.7
P1.0 - P1.7
1101
High Z
XADDR
High Z
RDY/BSY
23
3390E–MICRO–6/08
26. Page Write 4K Code
Function:
1. Programs 1 page (1 to 32 bytes) of data into the Code Memory array.
2. X-address (page) determined by previous Load-X command.
3. Y-address (offset) incremented by positive pulse on XTAL1.
4. 1 byte of data is loaded from Port P1 for the current X- and Y-address by a low pulse on
P3.2.
Usage:
1. Execute the Load-X command to set the page address and reset the offset.
2. Apply “1110” TestCode to P3.7, P3.5, P3.4, P3.3.
3. Drive Port P1 with 8-bit data.
4. Pulse P3.2 low for 1 µs to load the data from Port P1.
5. For additional bytes (up to 32), pulse XTAL1 high for at least 100 ns to increment the
Y-address and repeat steps 3 and 4 within 150 µs.
6. Wait 2 ms, monitor P3.1, or poll data.
Note:
It is possible to skip bytes by pulsing XTAL1 high multiple times before pulsing P3.2 low.
Figure 26-1. Page Write 4K Code Programming Sequence
P3.2
XTAL1
P3.3 - P3.7
1101
P1.0 - P1.7
XADDR
1110
DIN0
DIN1
DIN N-1
High Z
RDY/BSY
24
AT89S2051/S4051
3390E–MICRO–6/08
AT89S2051/S4051
27. Read 4K Code
Function:
1. Read 1 page (1 to 32 bytes) of data from the Code Memory array.
2. X-address (page) determined by previous Load-X command.
3. Y-address (offset) incremented by positive pulse on XTAL1.
Usage:
1. Execute the Load-X command to set the page address and reset the offset.
2. Apply “1100” TestCode to P3.7, P3.5, P3.4, P3.3.
3. Read 8-bit data on Port P1.
4. For additional bytes (up to 32), pulse XTAL1 high for at least 100 ns to increment the
Y-address and repeat step 3. The address will change on the falling edge of XTAL1.
Figure 27-1. Read 4K Code Programming Sequence
P3.2
XTAL1
P3.3 - P3.7
1101
P1.0 - P1.7
XADDR
1100
DOUT0
DOUT1
DOUT N-1
RDY/BSY
25
3390E–MICRO–6/08
28. Page Write User Signature Row
Function:
1. Programs 1 to 32 bytes of data into the User Signature Row.
2. X-address (page) should be 00H from a previous Load-X command.
3. Y-address (offset) incremented by positive pulse on XTAL1.
4. 1 byte of data is loaded from Port P1 for the current Y-address by a low pulse on P3.2.
5. Disabled if User Row Fuse bit is disabled.
Usage:
1. Execute the Load-X command to set the page to 00H and reset the offset.
2. Apply “0000” TestCode to P3.7, P3.5, P3.4, P3.3.
3. Drive Port P1 with 8-bit data.
4. Pulse P3.2 low for 1 µs to load the data from Port P1.
5. For additional bytes (up to 32), pulse XTAL1 high for at least 100 ns to increment the Yaddress and repeat steps 3 and 4 within 150 µs.
6. Wait 2 ms, monitor P3.1, or poll data.
Note:
It is possible to skip bytes by pulsing XTAL1 high multiple times before pulsing P3.2 low.
Figure 28-1. Page Write User Signature Row Sequence
P3.2
XTAL1
P3.3 - P3.7
1101
P1.0 - P1.7
00H
0000
DIN0
DIN1
DIN N-1
RDY/BSY
26
AT89S2051/S4051
3390E–MICRO–6/08
AT89S2051/S4051
29. Read User Signature Row
Function:
1. Reads 1 to 32 bytes of data from the User Signature Row.
2. X-address (page) should be 00H from a previous Load-X command.
3. Y-address (offset) incremented by positive pulse on XTAL1.
Usage:
1. Execute the Load-X command to set the page to 00H and reset the offset.
2. Apply “1000” TestCode to P3.7, P3.5, P3.4, P3.3.
3. Read 8-bit data on Port P1.
4. For additional bytes (up to 32), pulse XTAL1 high for at least 100 ns to increment the Yaddress and repeat step 3. The address will change on the falling edge of XTAL1.
Figure 29-1. Read User Signature Row Sequence
P3.2
XTAL1
P3.3 - P3.7
P1.0 - P1.7
1101
00H
1000
DOUT0
DOUT1
DOUT N-1
RDY/BSY
27
3390E–MICRO–6/08
30. Read Atmel Signature Row
Function:
1. Reads 1 to 32 bytes of data from the Atmel Signature Row.
2. X-address (page) should be 01H from a previous Load-X command.
3. Y-address (offset) incremented by positive pulse on XTAL1.
Usage:
1. Execute the Load-X command to set the page to 01H and reset the offset.
2. Apply “1000” TestCode to P3.7, P3.5, P3.4, P3.3.
3. Read 8-bit data on Port P1.
4. For additional bytes (up to 32), pulse XTAL1 high for at least 100 ns to increment the Yaddress and repeat step 3. The address will change on the falling edge of XTAL1.
Figure 30-1. Read Atmel Signature Row Sequence
P3.2
XTAL1
P3.3 - P3.7
P1.0 - P1.7
1101
01H
1000
DOUT0
DOUT1
DOUT N-1
RDY/BSY
28
AT89S2051/S4051
3390E–MICRO–6/08
AT89S2051/S4051
31. Write Lock Bits/User Fuses
Function:
1. Program Lock Bits 1 and 2.
2. Program user fuses.
Usage:
1) Apply “1111” TestCode to P3.7, P3.5, P3.4, P3.3.
3. Drive Port P1 with fuse data, bits [7:4] for fuses and bits [1:0] for lock bits.
4. Pulse P3.2 low for 1 µs.
5. Wait 4 ms, monitor P3.1, or poll data.
Figure 31-1. Write Lock Bits/User Fuses
P3.2
XTAL1
P3.3 - P3.7
P1.0 - P1.7
1111
High Z
DATA
High Z
RDY/BSY
32. Read Lock Bits/User Fuses
Function:
1. Read status of Lock Bits 1 and 2.
2. Read status of user fuses.
Usage:
1. Apply “0011” TestCode to P3.7, P3.5, P3.4, P3.3.
2. Read fuse data from Port P1, bits [7:4] for fuses and bits [1:0] for lock bits.
Figure 32-1. Read Lock Bits/User Fuses
P3.2
XTAL1
P3.3. - P3.7
P1.0 - P1.7
0011
High Z
DOUT
High Z
RDY/BSY
29
3390E–MICRO–6/08
Figure 32-2. Flash Programming and Verification Waveforms in Parallel Mode
VCC
RST/VPP
P3.2/PROG
P3.3...P3.7
PORT0
XTAL1
P3.1
(RDY/BSY)
tPWRUP
tPOR
t
HSTL
tPSTP
tASTP
tMSTP
LOADX
XADDR
tXTW
t
tPGW
tXLP
DSTP
DATA0
tAHLD
DATA1
tBLT
PAGE WRITE
DATAN
tDHLD
tPHX
tPHBL
tMSTP
tWC
LOADX
XADDR
DATA0
tMHLD
PAGE READ
DATA1
tRDT
tHSTL
DATAN
tVFY
tPWRDN
AT89S2051/S4051
30
3390E–MICRO–6/08
AT89S2051/S4051
Table 32-1.
Parallel Flash Programming and Verification Parameters
Symbol
Parameter
Min
Max
Units
VPP
Programming Enable Voltage
11.5
12.5
V
IPP
Programming Enable Current
1.0
mA
tPWRUP
Power-on to RST High
10
µs
tPOR
Power-on Reset Time
2
ms
tPSTP
PROG Setup to VPP High
10
µs
tHSTL
High Voltage Setting time
10
µs
tMSTP
Mode Setup to PROG or XTAL1
1
µs
tMHLD
Mode Hold after PROG or XTAL2
1
µs
tXTW
XTAL1 High Width
0.5
µs
tASTP
Address Setup to XTAL1 High
0.5
µs
tAHLD
Address Hold after XTAL1 Low
0.5
µs
tPGW
PROG Low Width
1
µs
tDSTP
Data Setup to PROG Low
0.5
µs
tDHLD
Data Hold after PROG High
0.5
µs
tXLP
XTAL1 Low to PROG Low
0.5
µs
tPHX
PROG High to XTAL1 High
0.5
µs
tBLT
Byte Load Period
150
µs
tPHBL
PROG High to BUSY Low
256
µs
tWC
Wire Cycle Time
4.5
ms
tRDT
Read Byte Time
tVFY
XTAL1 Low to Data Verify Valid
tPWRDN
RST Low to Power Off
1
µs
0.25
1
µs
µs
31
3390E–MICRO–6/08
33. In-System Programming (ISP) Specification
Atmel’s AT89S2051/S4051 offers 2K/4K bytes of In-System Programmable Flash code memory.
In addition, the device contains a 32-byte User Signature Row and a 32-byte read-only Atmel
Signature Row.
Table 33-1.
Memory Organization
Device #
Page Size
# Pages
Address Range
Page Range
AT89S2051
32 bytes
64
0000H - 07FFH
00H - 3FH
AT89S4051
32 bytes
128
0000H - 0FFFH
00H - 7FH
Figure 33-1. ISP Programming Device Connections
AT89S2051/S4051
2.7V to 5.5V
VCC
SCK(1)
P1.7
SERIAL IN
(MOSI)
P1.5
XTAL1
P1.6
RST
SERIAL OUT
(MISO)
VCC
GND
Note:
32
1. SCK frequency should be less than (XTAL frequency)/8.
AT89S2051/S4051
3390E–MICRO–6/08
AT89S2051/S4051
34. Serial Programming Command Summary
1010 1100
100x xxxx
xxxx xxxx
xxxx xxxx
Write Code Byte
0100 0000
Read Code Byte
0010 0000
Write Code Page(2)
0101 0000
Read Code Page(2)
0011 0000
Write User Fuses(3)
1010 1100
Read User Fuses(3)
0010 0001
Write Lock Bits(4)
1010 1100
Read Lock Bits(4)
0010 0100
Write User Signature Byte
0100 0010
xxxx xxxx
Read User Signature Byte
0010 0010
xxxx xxxx
Write User Signature Page(2)
0101 0010
xxxx xxxx
xxxx xxxx
Data 0 ... Data 31
(2)
0011 0010
xxxx xxxx
xxxx xxxx
Data 0 ... Data 31
0010 1000
xxxx xxxx
Notes:
xxxx
xxxx
0001
0 0000
xxx
xxx
A4
A3
A2
A1
A0
xxx
xxxx xxxx
xxxx xx
LB2
LB1
xxxx xxxx
xxxx
F3
F2
F1
F0
xxxx xxxx
xxxx xxxx
D7
D6
D5
D4
D3
D2
D1
D0
xxxx xxxx
Data 0 ... Data 31
D7
D6
D5
D4
D3
D2
D1
D0
xxxx xxxx
A4
A3
A2
A1
A0
F3
F2
F1
F0
xxxx xxxx
1110 0x
Data 0 ... Data 31
0 0000
xxxx xxxx
Byte ...
D7
D6
D5
D4
D3
D2
D1
D0
Read Atmel Signature Byte(5)
xxxx
A4
A3
A2
A1
A0
Read User Signature Page
xxxx
D7
D6
D5
D4
D3
D2
D1
D0
Chip Erase
D7
D6
D5
D4
D3
D2
D1
D0
xxxx xxxx
A7
A6
A5
A4
A3
A2
A1
A0
xxxx xxxx
A7
A6
A5
A4
A3
A2
A1
A0
0101 0011
A7
A6
A5
1010 1100
A7
A6
A5
Program Enable(1)
A11
A10
A9
A8
Byte 4
A11
A10
A9
A8
Byte 3
A11
A10
A9
A8
Byte 2
A11
A10
A9
A8
Byte 1
LB2
LB1
Command
1. Program Enable must be the first command issued after entering into the serial programming mode.
2. All 32 Data bytes must be written/read.
3. Fuse Bit Definitions:
Bit 0
ISP Enable*
Enable = 0/Disable = 1
Bit 1
x2 Clock
Enable = 0/Disable = 1
Bit 2
User Row Programming
Enable = 0/Disable = 1
Bit 3
XTAL Osc Bypass**
Enable = 0/Disable = 1
*The ISP Enable Fuse must be enabled before entering ISP mode.
When disabling the ISP fuse during ISP mode, the current fuse state will remain active until RST is brought low.
**Any change will only take effect after the next power-down/power-up cycle event.
4. Lock Bit Definitions:
Bit 0
Lock Bit 1
Locked = 0/Unlocked = 1
Bit 1
Lock Bit 2
Locked = 0/Unlocked = 1
5. Atmel Signature Bytes:
AT89S2051:
Address
00H = 1EH
01H = 23H
02H = FFH
AT89S4051:
Address
00H = 1EH
01H = 43H
02H = FFH
33
3390E–MICRO–6/08
35. Power-up Sequence
Execute this sequence to power-up the device before programming.
1. Apply power between VCC and GND pins.
2. Keep SCK (P1.7) at GND.
3. Wait 10 µs and bring RST to “H”.
4. If a crystal is connected between XTAL1 and XTAL2, wait at least 10 ms; otherwise,
apply a 3 - 24 MHz clock to XTAL1 and wait 4 ms.
Figure 35-1. ISP Power-up Sequence
VCC
RST
XTAL1
P1.7/SCK
P1.6/MISO
High Z
P1.5/MOSI
36. ISP Start Sequence
Execute this sequence to enter ISP when the device is already operational.
1. Bring SCK (P1.7) to GND.
2. Tri-state MISO (P1.6).
3. Bring RST to “H”.
Figure 36-1. ISP Start Sequence
VCC
RST
XTAL1
P1.7/SCK
P1.6/MISO
High Z
P1.5/MOSI
34
AT89S2051/S4051
3390E–MICRO–6/08
AT89S2051/S4051
37. Power-down Sequence
Execute this sequence to power-down the device after programming.
1. Set XTAL1 to “L” if a crystal is not used.
2. Bring RST to “L”.
3. Tri-state MOSI (P1.5).
Figure 37-1. ISP Power-down Sequence
VCC
RST
XTAL1
P1.7/SCK
High Z
P1.6/MISO
P1.5/MOSI
High Z
38. ISP Byte Sequence
1. Data shifts in/out MSB first.
2. MISO changes at rising of SCK.
3. MOSI is sampled at falling edge of SCK.
Figure 38-1. ISP Byte Sequence
P1.7/SCK
P1.6/MISO
7
6
5
4
3
2
1
0
3
2
1
0
data is sampled
P1.5/MOSI
7
6
5
4
39. ISP Command Sequence
1. Byte Format: 4 byte packet (3 header bytes + 1 data byte)
2. Page Format: 35 byte packet (3 header bytes + 32 data bytes)
3. All bytes are required, even if they are don’t care.
Figure 39-1. ISP Command Sequence
SCK
SO
7
???
7
OPCODE
0 7
???
7
ADDRH
07
???
7
ADDRL
0 7
DATAOUT
0
DATAIN
0
SI
0
0
0
7
35
3390E–MICRO–6/08
40. Absolute Maximum Ratings*
Operating Temperature ................................. -55°C to +125°C
*NOTICE:
Stresses beyond 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
other conditions beyond those indicated in the
operational sections of this specification is not
implied. Exposure to absolute maximum rating
conditions for extended periods may affect
device reliability.
Storage Temperature ..................................... -65°C to +150°C
Voltage on Any Pin with Respect to Ground......-0.7V to +6.2V
Maximum Operating Voltage ............................................ 5.5V
DC Output Current............. 25.0 mA (15.0 mA for AT89S4051)
41. DC Characteristics
TA = -40°C to 85°C, VCC = 2.7V to 5.5V (unless otherwise noted)
Symbol
Parameter
VIL
Input Low-voltage
VIH
Input High-voltage
VIH1
Input High-voltage
VOL
Output Low-voltage
Condition
(Except XTAL1, RST)
(XTAL1, RST)
(1)
(Ports 1, 3)
Min
Max
Units
-0.5
0.2 VCC - 0.1
V
0.2 VCC + 0.9
VCC + 0.5
V
0.7 VCC
VCC + 0.5
V
0.5
V
IOL = 10 mA, VCC = 2.7V, TA = 85°C
IOH = -80 µA, VCC = 5V ± 10%
2.4
V
IOH = -30 µA
0.75 VCC
V
IOH = -12 µA
0.9 VCC
V
VOH
Output High-voltage (Ports 1, 3)
IIL
Logical 0 Input Current
(Ports 1, 3)
VIN = 0.45V
-50
µA
ITL
Logical 1 to 0 Transition Current
(Ports 1, 3)
VIN = 2V, VCC = 5V ± 10%
-350
µA
ILI
Input Leakage Current
(Port P1.0, P1.1)
0 < VIN < VCC
±10
µA
VOS
Comparator Input Offset Voltage
VCC = 5V
20
mV
VCM
Comparator Input Common
Mode Voltage
0
VCC
V
RRST
Reset Pull-down Resistor
50
150
KΩ
CIO
Pin Capacitance
10
pF
Active Mode, 24/12 MHz, VCC =
5V/3V
10.5/3.5
mA
Idle Mode, 24/12 MHz, VCC = 5V/3V
P1.0 & P1.1 = 0V or VCC
4.5/2.5
mA
VCC = 5V, P1.0 & P1.1 = 0V or VCC(3)
10
µA
VCC(3)
5
µA
Power Supply Current (without
the )
ICC
Power-down Mode(2)
Notes:
36
Test Freq. = 1 MHz, TA = 25°C
VCC = 3V, P1.0 & P1.1 = 0V or
1. Under steady state (non-transient) conditions, IOL must be externally limited as follows:
Maximum IOL per port pin: 10 mA
Maximum total IOL for all output pins: 25 mA (15 mA for AT89S4051)
If IOL exceeds the test condition, VOL may exceed the related specification. Pins are not guaranteed to sink current greater
than the listed test conditions.
2. Minimum VCC for Power-down is 2V.
3. P1.0 and P1.1 are comparator inputs and have no internal pullups. They should not be left floating.
AT89S2051/S4051
3390E–MICRO–6/08
AT89S2051/S4051
42. External Clock Drive Waveforms
43. External Clock Drive
VCC = 2.7V to 5.5V
Symbol
Parameter
Min
Max
Units
1/tCLCL
Frequency
0
24
MHz
tCLCL
Clock Period
41.6
ns
tCHCX
High Time
12
ns
tCLCX
Low Time
12
ns
tCLCH
Rise Time
5
ns
tCHCL
Fall Time
5
ns
37
3390E–MICRO–6/08
44. Serial Port Timing: Shift Register Mode Test Conditions
The values in this table are valid for VCC = 2.7V to 5.5V and Load Capacitance = 80 pF.
Variable
Symbol
Parameter
Min
Max
Units
tXLXL
Serial Port Clock Cycle Time
12tCLCL -15
µs
tQVXH
Output Data Setup to Clock Rising Edge
10tCLCL -15
ns
tXHQX
Output Data Hold after Clock Rising Edge
2tCLCL -15
ns
tXHDX
Input Data Hold after Clock Rising Edge
tCLCL
ns
tXHDV
Input Data Valid to Clock Rising Edge
0
ns
45. Shift Register Mode Timing Waveforms
46. AC Testing Input/Output Waveforms(1)
Note:
1. AC Inputs during testing are driven at VCC - 0.5V 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.
47. Float Waveforms(1)
Note:
38
1. For timing purposes, a port pin is no longer floating when a 100 mV change from load voltage
occurs. A port pin begins to float when 100 mV change from the loaded VOH/VOL level occurs.
AT89S2051/S4051
3390E–MICRO–6/08
AT89S2051/S4051
48. ICC Test Condition, Active Mode, All Other Pins are Disconnected
VCC
ICC
VCC
RST
VCC
P1, P3
XTAL2
(NC)
CLOCK SIGNAL
XTAL1
VSS
49. ICC Test Condition, Idle Mode, All Other Pins are Disconnected
VCC
ICC
VCC
RST
VCC
P1, P3
XTAL2
(NC)
CLOCK SIGNAL
XTAL1
VSS
50. Clock Signal Waveform for ICC Tests in Active and Idle Modes,
tCLCH = tCHCL = 5 ns
VCC - 0.5V
0.45V
0.7 VCC
tCHCX
0.2 VCC - 0.1V
tCHCL
tCLCH
tCHCX
tCLCL
51. ICC Test Condition, Power-down Mode, All Other Pins are Disconnected,
VCC = 2V to 5.5V
VCC
ICC
RST
VCC
VCC
P1, P3
(NC)
XTAL2
XTAL1
VSS
39
3390E–MICRO–6/08
52. ICC (Active Mode) Measurements
o
ICC Active @ 25 C
ICC Active (mA)
4.00
3.50
3.0V
3.00
4.0V
2.50
5.0V
2.00
1.50
1
2
3
4
5
6
7
8
9
10
11
12
Frequency (MHz)
o
ICC Active @ 90 C
ICC Active (mA)
4.00
3.50
3.0 V
3.00
4.0 V
2.50
5.0 V
2.00
1.50
1
2
3
4
5
6
7
8
9
10
11
12
Frequency (MHz)
40
AT89S2051/S4051
3390E–MICRO–6/08
AT89S2051/S4051
53. ICC (Idle Mode) Measurements
ICC Idle vs. Frequency
T = 25°C
3
ICC (mA)
2.5
2
1.5
Vcc=3V
Vcc=4V
1
Vcc=5v
0.5
0
0
5
10
15
20
25
Frequency (MHz)
54. ICC (Power Down Mode) Measurements
ICC in Power-down
ICC Pwd (uA)
2.5
2
0 deg C
1.5
25 deg C
1
90 deg C
0.5
0
1
2
3
4
5
6
7
VCC (V)
41
3390E–MICRO–6/08
55. Ordering Information
55.1
Green Package Option (Pb/Halide-free)
Speed
(MHz)
Power
Supply
24
2.7V to 5.5V
Ordering Code
Package
AT89S2051/S4051-24PU
AT89S2051/S4051-24SU
20P3
20S2
Operation Range
Industrial
(-40° C to 85° C)
Package Type
20P3
20-lead, 0.300” Wide, Plastic Dual In-line Package (PDIP)
20S2
20-lead, 0.300” Wide, Plastic Gull Wing Small Outline (SOIC)
42
AT89S2051/S4051
3390E–MICRO–6/08
AT89S2051/S4051
56. Package Information
56.1
20P3 – PDIP
D
PIN
1
E1
A
SEATING PLANE
A1
L
B
B1
e
E
COMMON DIMENSIONS
(Unit of Measure = mm)
C
eC
eB
Notes:
1. This package conforms to JEDEC reference MS-001, Variation AD.
2. Dimensions D and E1 do not include mold Flash or Protrusion.
Mold Flash or Protrusion shall not exceed 0.25 mm (0.010").
SYMBOL
MIN
NOM
MAX
A
–
–
5.334
A1
0.381
–
–
D
24.892
–
26.924
E
7.620
–
8.255
E1
6.096
–
7.112
B
0.356
–
0.559
B1
1.270
–
1.551
L
2.921
–
3.810
C
0.203
–
0.356
eB
–
–
10.922
eC
0.000
–
1.524
e
NOTE
Note 2
Note 2
2.540 TYP
1/23/04
R
2325 Orchard Parkway
San Jose, CA 95131
TITLE
20P3, 20-lead (0.300"/7.62 mm Wide) Plastic Dual
Inline Package (PDIP)
DRAWING NO.
20P3
REV.
D
43
3390E–MICRO–6/08
56.2
44
20S2 – SOIC
AT89S2051/S4051
3390E–MICRO–6/08
AT89S2051/S4051
57. Revision History
Revision No.
History
•
•
Revision D – Feb. 2007
Revision E – June 2008
•
Removed Preliminary Status.
Added the qualifier “x1 and x2 Modes” to the Static Operation
range.
Changed the value ranges for Capacitors C1 and C2 in Figure 5-1
on page 4.
Changed the trigger level for the BOD from 2.2V to 2.0V.
•
Removed Standard Packaging Offering.
•
45
3390E–MICRO–6/08
Headquarters
International
Atmel Corporation
2325 Orchard Parkway
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USA
Tel: 1(408) 441-0311
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3390E–MICRO–6/08