EMS6500 EM Microelectronic, EMS6500 Datasheet - Page 71

• Manufacturer Part Number: EMS6500
• Description: Microcontroller Development System 4-bit (Emmon), Simulators 4-bit
• Manufacturer: EM Microelectronic

Copyright  2003 EM Microelectronic-Marin SA
2.2.
2.3.
2.4.
2.5.
2.6.
2.7.
Port B is a bitwise select input output port. The LED and buttons show (address
075H) the state of port B. When the port is input the state can be changed using the
corresponding push buttons. When the port is set to output (address 076H) the
button is set to NC (not connected) and the LED indicates the state of the output
port. Consequently the possible combinations for the LED and button states are
shown in Table 2-3.
Port C can be configured as either a 4 bit input port or a 4 bit output port (bit 1
address 07CH). The possible combinations for the LED and button states are the
same as for port B and are shown in Table 2-3. Port C has maskable interrupt
capabilities (address 079H). The state of the interrupt mask is show next to the port
and can have the states shown in Table 2-2.
Port D can configured as either a 4 bit input port or a 4 bit output port (bit 2 address
07CH). When port D is set to output and serial write mode is selected (bit3 address
068H) the serial clock is output on port D0 and the serial data on port D1. The
possible combinations for the LED and button states for port D are shown in Table
2-3. When in serial write mode the symbol « NC » is replaced by « SCK » (serial
clock) for port D0 and « SD » (serial data) for port D1.
The selected prescaler interrupt frequency is indicated. This corresponds to the
value written to bits 0-1 in the register 07DH.
Indicates the output frequency selected and corresponds to bits 0-1 in the register
07EH.
LED state
Port B
Port C
Port D / Serial Write Buffer
Prescaler
Buzzer
Timer
Red
Yellow
Red
Yellow
Button
Table 2-3 Possible states for input output port.
NC
NC
Fig. 2-2 Timer parameters
H
L
State
Port input and high
Port input and low
Port output and high
Port output and low
7
Peripheral Interface
www.emmicroelectronic.com
EM66xx
Binder 4.3-01/03 Rev. B/495