80C451 Datasheet, PDF (9/22 Pages) NXP Semiconductors – 80C51 8-bit microcontroller family 4K/128 OTP/ROM/ROMless, expanded I/O

Philips Semiconductors
80C51 8-bit microcontroller family
4K/128 OTP/ROM/ROMless, expanded I/O
Product specification
80C451/83C451/87C451
Table 3. Control Status Register (CSR)
Bit 7
Bit 6
Bit 5
Bit 4
Bit 3
Bit 2
Bit 1
Bit 0
MB1
MB0
MA1
MA0
OBFC
IDSM
OBF
IBF
BFLAG Mode Select
AFLAG Mode Select
Output Buffer
Flag Clear
Mode
Input Data
Strobe Mode
Output Buffer
Flag Full
Input Buffer
Flag Full
0/0 = Logic 0 output*
0/1 = Logic 1 output*
1/0 = IBF output
1/1 = PE input
(0 = Select)
(1 = Disable I/O)
0/0 = Logic 0 output*
0/1 = Logic 1 output*
1/0 = OBF output
1/1 = SEL input
(0 = Select)
(1 = Control/status)
0 = Negative
edge of ODS
1 = Positive
edge o ODS
0 = Positive
edge of IDS
1 = Low level
of IDS
0 = Output
data buffer
empty
1 = Output
data buffer full
0 = Input data
buffer empty
1 = Input data
buffer full
NOTE:
* Output-always mode: MB1 = 0, MA1 = 1, and MA0 = 0. In this mode, port 6 is always enabled for output. ODS only clears the OBF flag.
ABSOLUTE MAXIMUM RATINGS^{1, 2, 3}
PARAMETER
RATING
UNIT
Operating temperature under bias
0 to +70
°C
Storage temperature range
–65 to +150
°C
Voltage on any other pin to V_SS
–0.5 to +6.5
V
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 maxima.
3. Parameters are valid over operating temperature range unless otherwise specified. All voltages are with respect to V_SS unless otherwise
noted.
1998 May 01
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