p87c453ebaa NXP Semiconductors, p87c453ebaa Datasheet - Page 13

• Manufacturer Part Number: p87c453ebaa
• Description: 80c51 8-bit Microcontroller Family 8k/256 Otp/rom, Expanded I/o
• Manufacturer: NXP Semiconductors

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Philips Semiconductors
Table 3. Special Function Register Addresses
Table 4. Control Status Register (CSR)
NOTE:
1998 Apr 23
80C51 8-bit microcontroller family
8K/256 OTP/ROM, expanded I/O
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.
Port 4
Port 5
Port 6 data
Port 6 control status
Slave address
Slave address mask
Auxiliary Register
Bit 7
MB1
1/0 = IBF output
1/1 = PE input
BFLAG Mode Select
0/0 = Logic 0 output*
0/1 = Logic 1 output*
(0 = Select)
(1 = Disable I/O)
Name
Bit 6
MB0
REGISTER ADDRESS
(CSR.4/.5)
AFLAG
OUTPUT BUFFER
FULL (CSR.1)
MODE
AFLAG
Bit 5
MA1
BFLAG/ODS
BFLAG
0/0 = Logic 0 output*
0/1 = Logic 1 output*
AFLAG Mode Select
1/0 = OBF output
(CSR.6/.7)
1/1 = SEL input
(0 = Select)
INPUT BUFFER
FULL (CSR.0)
(1 = Control/status)
MODE
Symbol
SADDR
SADEN
AUXR
CSR
P4
P5
P6
CONTROL/STATUS
ODS
REGISTER (CSR)
Figure 8. Port 6 Block Diagram
Bit 4
MA0
Address
DRIVERS
OUTPUT
PORT 6
INTERNAL BUS
C0
C8
D8
E8
A9
B9
8E
MUX
OUTPUT BUFFER
(P6 WRITE)
13
Output Buffer
edge of ODS
0 = Negative
edge o ODS
1 = Positive
MSB
Flag Clear
C7
CF
DF
EF
OBFC
Mode
Bit 3
(P6 READ)
BUFFER
CE
DE
INPUT
C6
EE
1 = Low level
Strobe Mode
0 = Positive
edge of IDS
Input Data
CD
DD
ED
C5
of IDS
IDSM
Bit 2
SELECT (CSR.2)
EDGE/LEVEL
BIT ADDRESS
MODE
CC
DC
EC
C4
IDS
IDS
SU00087
data buffer full
Output Buffer
0 = Output
data buffer
1 = Output
CB
DB
EB
C3
83C453/87C453
Flag Full
empty
Bit 1
OBF
Preliminary specification
CA
DA
EA
C2
0 = Input data
1 = Input data
buffer empty
Input Buffer
C1
C9
D9
E9
buffer full
Flag Full
Bit 0
IBF
LSB
C0
C8
D8
E8