TN80C31BH1SF88 Intel, TN80C31BH1SF88 Datasheet - Page 6

• Manufacturer Part Number: TN80C31BH1SF88
• Description: IC MPU 8-BIT 5V 16MHZ EXT 44PLCC
• Manufacturer: Intel
• Series: 80Cr

Specifications of TN80C31BH1SF88

• Rohs Status: RoHS non-compliant
• Core Processor: MCS 51
• Core Size: 8-Bit
• Speed: 16MHz
• Connectivity: SIO
• Peripherals: POR
• Number Of I /o: 32
• Program Memory Type: ROMless
• Ram Size: 128 x 8
• Voltage - Supply (vcc/vdd): 4.5 V ~ 5.5 V
• Oscillator Type: External
• Operating Temperature: -40°C ~ 85°C
• Package / Case: 44-PLCC
• Eeprom Size: -
• Program Memory Size: -
• Data Converters: -
• Other names: 810026

87C51/80C51BH/80C31BH
IDLE MODE
In Idle Mode, the CPU puts itself to sleep while all
the on-chip peripherals remain active. The mode is
invoked by software. The content of the on-chip
RAM and all the Special Functions Registers remain
unchanged during this mode. The Idle Mode can be
terminated by any enabled interrupt or by a hard-
ware reset.
It should be noted that when Idle is terminated by a
hardware reset, the device normally resumes pro-
gram execution, from where it left off, up to two ma-
chine 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 terminat-
ed by reset, the instruction following the one that
invokes Idle should not be one that writes to a port
pin or to external memory.
POWER DOWN MODE
To save even more power, a Power Down mode 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 val-
ues until the Power Down mode is transmitted.
On the 87C51/BH either a hardware reset or an ex-
ternal interrupt can cause an exit from Power Down.
Reset redefines all the SFR's but does not change
6
Idle
Idle
Power Down
Power Down
Mode
Table 2. Status of the External Pins during Idle and Power Down
Program
Memory
External
External
Internal
Internal
ALE
1
1
0
0
PSEN
1
1
0
0
the on-chip RAM. An external interrupt allows both
the SFRs and on-chip RAM to retain their values.
To properly terminate Power Down, the reset or ex-
ternal interrupt should not be executed before V
restored to its normal operating level, and must be
held active long enough for the oscillator to restart
and stabilize (normally less than 10 ms).
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
RET1 will be the one following the instruction that
put the device into Power Down.
DESIGN CONSIDERATIONS
PORT0
Float
Float
Data
Data
Exposure to light when the device is in operation
may cause logic errors. For this reason, it is sug-
gested that an opaque label be placed over the
window when the die is exposed to ambient light.
The 87C51/BH now have some additional fea-
tures. The features are: asynchronous port reset,
4 interrupt priority levels, power off flag, ALE dis-
able, serial port automatic address recognition,
serial port framing error detection, 64-byte en-
cryption array, and 3 program lock bits. These
features cannot be used with the older versions
of 80C51BH/80C31BH. The newer version of
80C51BH/80C31BH will have change identifier
"A'' appended to the lot number.
PORT1
Data
Data
Data
Data
Address
PORT2
Data
Data
Data
PORT3
Data
Data
Data
Data
CC
is