MYSON
TECHNOLOGY
MTV112A
(Rev 1.9)
MTV112A Revision 1.9 05/18/2001
4/20
3.0 FUNCTIONAL DESCRIPTION
1. 8051 CPU Core
MTV112A includes all 8051 functions with the following exceptions:
1.1 PSEN, ALE, RD and WR pins are disabled. The external RAM access is restricted to XFRs within
MTV112A.
1.2 Port 0, port 3.3, and ports 3.5 ~ 3.7 are not general-purpose I/O ports. They are dedicated to monitor
control or DAC pins.
1.3 INT1 and T1 input pins are not provided.
1.4 Ports 2.4 ~ 2.7 are shared with DAC pins; ports 3.0 ~ 3.2, and port3.4 are shared with monitor control
pins.
In addition, there are 2 timers, 5 interrupt sources and a serial interface compatible with the standard 8051.
The Txd/Rxd (P3.0/P3.1) pins are shared with DDC interface. INT0/T0 pins are shared with IIC interface. An
extra option can be used to switch the INT0 source from P3.2 to P2.0. This feature maintains an external
interrupt source when IIC interface is enabled.
Note: All registers listed in this document reside in the external RAM area (XFR). For the internal
RAM memory map please refer to the 8051 spec.
Reg name
addr
bit7
bit6
bit5
bit4
bit3
bit2
bit1
bit0
PADMOD 30h (w)
SINT0
IICF
DDCE
IICE
DA13E
DA12E
DA11E
DA10E
PADMOD 31h (w)
P57E
P56E
P55E
P54E
P53E
P52E
P51E
P50E
PADMOD 37h (w)
-
-
-
-
-
-
-
MORE
SINT0 = 1
→ INT0 source is pin #21.
= 0
→ INT0 source is pin #12.
IICF
= 1
→ Selects 400kHz master IIC speed.
= 0
→ Selects 100kHz master IIC speed.
DDCE = 1
→ Pin #10 is HSCL; pin #11 is HSDA.
= 0
→ Pin #10 is P3.0/Rxd; pin #11 is P3.1/Txd.
IICE
= 1
→ Pin #12 is ISDA; pin #14 is ISCL.
= 0
→ Pin #12 is P3.2/(INT0*); pin #14 is P3.4/T0.
DA13E = 1
→ Pin #25 is DA13.
= 0
→ Pin #25 is P2.4.
DA12E = 1
→ Pin #26 is DA12.
= 0
→ Pin #26 is P2.5.
DA11E = 1
→ Pin #27 is DA11.
= 0
→ Pin #27 is P2.6.
DA10E = 1
→ Pin #28 is DA10.
= 0
→ Pin #28 is P2.7.
P57E
= 1
→ Pin #32 is P5.7.
= 0
→ Pin #32 is DA7.
P56E
= 1
→ Pin #33 is P5.6.
= 0
→ Pin #33 is DA6.
P55E
= 1
→ Pin #34 is P5.5.
= 0
→ Pin #34 is DA5.
P54E
= 1
→ Pin #35 is P5.4.
= 0
→ Pin #35 is DA4.
P53E
= 1
→ Pin #36 is P5.3.
= 0
→ Pin #36 is DA3.
P52E
= 1
→ Pin #37 is P5.2.
= 0
→ Pin #37 is DA2.