P87C51FB-4B,557 NXP Semiconductors, P87C51FB-4B,557 Datasheet - Page 21

• Manufacturer Part Number: P87C51FB-4B,557
• Manufacturer: NXP Semiconductors

Philips Semiconductors
2000 Aug 07
80C51 8-bit microcontroller family
8K–64K/256–1K OTP/ROM/ROMless, low voltage (2.7V–5.5V),
low power, high speed (33MHz)
Figure 9. UART Multiprocessor Communication, Automatic Address Recognition
START
BIT
IN UART MODE 2 OR MODE 3 AND SM2 = 1:
– WHEN OWN ADDRESS RECEIVED, CLEAR SM2 TO RECEIVE DATA BYTES
– WHEN ALL DATA BYTES HAVE BEEN RECEIVED: SET SM2 TO WAIT FOR NEXT ADDRESS.
D0
SM0 / FE
INTERRUPT IF REN=1, RB8=1 AND “RECEIVED ADDRESS” = “PROGRAMMED ADDRESS”
RECEIVED ADDRESS D0 TO D7
SMOD1
PROGRAMMED ADDRESS
D0
0 : SCON.7 = SM0
1 : SCON.7 = FE
D1
SMOD0
SM1
D1
Figure 8. UART Framing Error Detection
D2
SM2
SM0
D2
–
1
1
D3
REN
SM1
D3
POF
DATA BYTE
1
0
SET FE BIT IF STOP BIT IS 0 (FRAMING ERROR)
SM0 TO UART MODE CONTROL
D4
21
TB8
D4
SM2
GF1
COMPARATOR
D5
1
D5
RB8
GF0
REN
1
D6
D6
8XC51RA+/RB+/RC+/RD+/80C51RA+
PD
TB8
TI
D7
X
D7
RB8
IDL
D8
RI
MODE 2, 3
ONLY IN
8XC51FA/FB/FC/80C51FA
D8
SCON
(98H)
PCON
(87H)
TI
STOP
BIT
SU01191
RI
Product specification
8XC54/58
SU00045
SCON
(98H)