ST16C654 EXAR [Exar Corporation], ST16C654 Datasheet - Page 9

• Manufacturer Part Number: ST16C654
• Description: 2.97V TO 5.5V QUAD UART WITH 64-BYTE FIFO
• Manufacturer: EXAR [Exar Corporation]

ST16C654/654D
2.97V TO 5.5V QUAD UART WITH 64-BYTE FIFO
REV. 5.0.0
The CPU interface is 8 data bits wide with 3 address lines and control signals to execute data bus read and
write transactions. The 654 data interface supports the Intel compatible types of CPUs and it is compatible to
the industry standard 16C550 UART. No clock (oscillator nor external clock) is required to operate a data bus
transaction. Each bus cycle is asynchronous using CS# A-D, IOR# and IOW# or CS#, R/W#, A4 and A3 inputs.
All four UART channels share the same data bus for host operations. A typical data bus interconnection for
Intel and Motorola mode is shown in
F
2.0 FUNCTIONAL DESCRIPTIONS
2.1
IGURE
4. ST16C654/654D T
CPU Interface
8 $ 5 7 B 5 ( 6 ( 7
8 $ 5 7 B 5 ( 6 ( 7
8 $ 5 7 B & 6 &
8 $ 5 7 B & 6 '
8 $ 5 7 B & 6 $
8 $ 5 7 B & 6 %
8 $ 5 7 B , 1 7 &
8 $ 5 7 B , 1 7 '
8 $ 5 7 B , 1 7 $
8 $ 5 7 B , 1 7 %
8 $ 5 7 B & 6
8 $ 5 7 B , 5 4
5  :
, 2 :
, 2 5
9 & &
$ 
$ 
$ 
$ 
$ 
$ 
' 
' 
' 
' 
' 
' 
' 
' 
' 
' 
' 
' 
' 
' 
' 
' 
$ 
$ 
YPICAL
0 R W R U R O D ' D W D % X V   0 R G H , Q W H U F R Q Q H F W L R Q V
I n t e l D a t a B u s ( 1 6 M o d e ) I n t e r c o n n e c t i o n s
Figure
I
NTEL
/M
4.
OTOROLA
Q R F R Q Q H F W
Q R F R Q Q H F W
Q R F R Q Q H F W
9 & &
9 & &
9
D
ATA
    
    
& 6 %
& 6 &
& 6 '
, 2 :
& 6 $
5 ( 6 ( 7
, 2 5
, 2 :
, 2 5
& 6 &
& 6 '
& 6 $
& 6 %
, 1 7 $
, 1 7 %
, 1 7 &
, 1 7 '
5 ( 6 ( 7
, 1 7 $
, 1 7 %
, 1 7 &
, 1 7 '
' 
' 
' 
' 
' 
' 
' 
' 
' 
' 
' 
' 
' 
' 
' 
' 
$ 
$ 
$ 
$ 
$ 
$ 
B
US
& K D Q Q H O '
& K D Q Q H O '
& K D Q Q H O &
& K D Q Q H O &
& K D Q Q H O $
& K D Q Q H O %
& K D Q Q H O $
& K D Q Q H O %
I
8 $ 5 7
8 $ 5 7
8 $ 5 7
8 $ 5 7
8 $ 5 7
8 $ 5 7
8 $ 5 7
8 $ 5 7
NTERCONNECTIONS
' 7 5 $
' 6 5 $
' 7 5 $
' 6 5 $
5 7 6 $
& 7 6 $
W R & K $
W R & K $
W R & K $
5 7 6 $
& 7 6 $
W R & K $
W R & K $
W R & K $
6 L P L O D U
6 L P L O D U
6 L P L O D U
6 L P L O D U
6 L P L O D U
6 L P L O D U
& ' $
& ' $
* 1 '
* 1 '
5 , $
5 , $
9 & &
7 ; $
5 ; $
9 & &
7 ; $
5 ; $
9 & &
9 & &
6 H U L D O , Q W H U I D F H R I
6 H U L D O , Q W H U I D F H R I
6 H U L D O , Q W H U I D F H R I
5 6    
6 H U L D O , Q W H U I D F H R I
5 6    
5 6    
5 6