80C554 Datasheet, PDF (15/76 Pages) NXP Semiconductors – 80C51 8-bit microcontroller . 6 clock operation 16K/512 OTP/ROM/ROMless, 7 channel 10 bit A/D, I2C, PWM, capture/compare, high I/O, 64L LQFP

Philips Semiconductors
80C51 8-bit microcontroller – 6 clock operation
16K/512 OTP/ROM/ROMless, 7 channel 10 bit A/D, I²C, PWM,
capture/compare, high I/O, 64L LQFP
Preliminary specification
80C554/83C554/87C554
D0
D1
D2
D3
D4
D5
D6
D7
D8
START
BIT
DATA BYTE
ONLY IN STOP
MODE 2, 3 BIT
SET FE BIT IF STOP BIT IS 0 (FRAMING ERROR)
SM0 TO UART MODE CONTROL
SM0 / FE SM1
SM2
REN
TB8
RB8
TI
RI
SCON
(98H)
SMOD1 SMOD0
POF
0 : S0CON.7 = SM0
1 : S0CON.7 = FE
WLE
GF1
GF0
PD
Figure 9. UART Framing Error Detection
IDL
PCON
(87H)
SU00982
D0
D1
D2
D3
D4
D5
D6
D7
D8
SM0
SM1
SM2
REN
TB8
RB8
TI
1
1
1
0
1
1
X
RI
SCON
(98H)
RECEIVED ADDRESS D0 TO D7
PROGRAMMED ADDRESS
COMPARATOR
IN UART MODE 2 OR MODE 3 AND SM2 = 1:
INTERRUPT IF REN=1, RB8=1 AND “RECEIVED ADDRESS” = “PROGRAMMED ADDRESS”
– WHEN OWN ADDRESS RECEIVED, CLEAR SM2 TO RECEIVE DATA BYTES
– WHEN ALL DATA BYTES HAVE BEEN RECEIVED: SET SM2 TO WAIT FOR NEXT ADDRESS.
Figure 10. UART Multiprocessor Communication, Automatic Address Recognition
SU00045
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 b used and which bits are “don’t care”. The SADEN
mask can 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 =
SADEN =
Given =
1100 0000
1111 1101
1100 00X0
Slave 1
SADDR =
SADEN =
Given =
1100 0000
1111 1110
1100 000X
In the above 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.
2000 Nov 10
15