UART Pins
The HT48RU80/HT48CU80 devices contain an internal Universal Asynchronous Receiver/Trans
-
mitter UART function, which requires two external pins for their serial connection to external de
-
vices. These pins known as TX and RX are pin-shared with I/O pins PC0 and PC1 respectively.
Chapter 1 Hardware Structure
39
V
D D
M
U
X
R e a d D a t a R e g i s t e r
D
Q
C K
S
D
Q
C K
S
C o n t r o l B i t
P u l l - H i g h
O p t i o n
D a t a B u s
W r i t e C o n t r o l R e g i s t e r
C h i p R e s e t
R e a d C o n t r o l R e g i s t e r
W r i t e D a t a R e g i s t e r
D a t a B i t
I N T ( P C 0 / P G 0 o n l y )
Q
W e a k
P u l l - u p
P C 0 / I N T ( H T 4 8 R 1 0 A - 1 / H T 4 8 C 1 0 - 1 )
P G 0 / I N T ( H T 4 8 R 3 0 A - 1 / H T 4 8 C 3 0 - 1
H T 4 8 R 5 0 A - 1 / H T 4 8 C 5 0 - 1 )
P B 2 / I N T 1 ( H T 4 8 R U 8 0 / H T 4 8 C U 8 0 )
P C 0 / T M R ( H T 4 8 R 3 0 A - 1 / H T 4 8 C 3 0 - 1 )
P C 0 / T M R 0 ( H T 4 8 R 5 0 A - 1 / H T 4 8 C 5 0 - 1 )
P C 1 / T M R ( H T 4 8 R 5 0 A - 1 / H T 4 8 C 5 0 - 1 )
P C 5 / T M R 1 ( H T 4 8 R 1 0 A - 1 / H T 4 8 C 1 0 - 1 )
P B 3 / T M R 2 ( H T 4 8 R U 8 0 / H T 4 8 C U 8 0 )
O S C 1 / P C 3 ( H T 4 8 R 1 0 A - 1 / H T 4 8 C 1 0 - 1 )
O S C 1 / P G 1 ( H T 4 8 R 3 0 A - 1 / H T 4 8 C 3 0 - 1
H T 4 8 R 5 0 A - 1 / H T 4 8 C 5 0 - 1 )
O S C 2 / P G 2 ( H T 4 8 R 3 0 A - 1 / H T 4 8 C 3 0 - 1
H T 4 8 R 5 0 A - 1 / H T 4 8 C 5 0 - 1 )
O S C 2 / P C 4 ( H T 4 8 R 1 0 A - 1 / H T 4 8 C 1 0 - 1 )
T M R / T M R 0 / T M R 1 / T M R 2
( P C 0 / P C 1 / P C 5 / P B 3 o n l y )
I N T 1 ( P B 2 o n l y )
O S C 1 ( P C 3 / P G 1 o n l y )
O S C 2 ( P C 4 / P G 2 o n l y )
Q
PB2~PB7, PC, PD, PE, PF and PG Input/Output Ports
V
D D
M
U
X
M
U
X
R e a d D a t a R e g i s t e r
D
Q
C K
S
D
Q
C K
Q
S
C o n t r o l B i t
P u l l - H i g h
O p t i o n
D a t a B u s
W r i t e C o n t r o l R e g i s t e r
C h i p R e s e t
R e a d C o n t r o l R e g i s t e r
W r i t e D a t a R e g i s t e r
D a t a B i t
P C 0 / T X
Q
F r o m U A R T T X
U A R T E N & T X E N
PC0/TX Input/Output Port - HT48RU80/HT48CU80