HT46R52 Holtek Semiconductor, HT46R52 Datasheet - Page 14

• Manufacturer Part Number: HT46R52
• Description: (HT46R51 / HT46R52) A/D Type 8-Bit OTP MCU
• Manufacturer: Holtek Semiconductor

Input/Output Ports
There are 14 bidirectional input/output lines in the
microcontroller, labeled as PA, PB and PD, which are
mapped to the data memory of [12H], [14H] and [18H]
respectively. All of these I/O ports can be used for input
and output operations. For input operation, these ports
are non-latching, that is, the inputs must be ready at the
T2 rising edge of instruction MOV A,[m] (m=12H, 14H
or 18H). For output operation, all the data is latched and
remains unchanged until the output latch is rewritten.
Rev. 1.40
Bit No.
0
1
2
3
4
5
6
7
Label
PSC0
PSC1
PSC2
TON
TM0
TM1
TE
Defines the prescaler stages, PSC2, PSC1, PSC0=
000: f
001: f
010: f
011: f
100: f
101: f
110: f
111: f
Defines the TMR active edge of the timer/event counter:
In Event Counter Mode (TM1,TM0)=(0,1):
1:count on falling edge;
0:count on rising edge
In Pulse Width measurement mode (TM1,TM0)=(1,1):
1: start counting on the rising edge, stop on the falling edge;
0: start counting on the falling edge, stop on the rising edge
Enable/disable timer counting (0=disable; 1=enable)
Unused bit, read as 0
Defines the operating mode, TM1, TM0:
01=Event count mode (external clock)
10=Timer mode (internal clock)
11=Pulse width measurement mode
00=Unused
INT
INT
INT
INT
INT
INT
INT
INT
=f
=f
=f
=f
=f
=f
=f
=f
SYS
SYS
SYS
SYS
SYS
SYS
SYS
SYS
/2
/4
/8
/16
/32
/64
/128
TMRC (0EH) Register
Input/Output Ports
14
Each I/O line has its own control register (PAC, PBC,
PDC) to control the input/output configuration. With this
control register, CMOS output or Schmitt trigger input
with or without pull-high resistor structures can be re-
configured dynamically under software control. To func-
tion as an input, the corresponding latch of the control
register must write 1 . The input source also depends
on the control register. If the control register bit is 1 ,
the input will read the pad state. If the control register bit
Function
HT46R51/HT46R52
July 12, 2005