MC9S08RG60 Datasheet, PDF (120/232 Pages) Motorola, Inc – Microcontrollers

Parallel Input/Output
8.6.5 Port E Registers (PTED, PTEPE, and PTEDD)
Port E pins used as general-purpose I/O pins are controlled by the port E data (PTED), data direction
(PTEDD), and pullup enable (PTEPE) registers.
PTED
PTEPE
PTEDD
Bit 7
Read:
PTED7
Write:
Reset: 0
6
PTED6
0
5
PTED5
0
4
PTED4
0
3
PTED3
0
2
PTED2
0
1
PTED1
0
Bit 0
PTED0
0
Read:
PTEPE7 PTEPE6 PTEPE5 PTEPE4 PTEPE3 PTEPE2 PTEPE1 PTEPE0
Write:
Reset: 0
0
0
0
0
0
0
0
Read:
PTEDD7 PTEDD6 PTEDD5 PTEDD4 PTEDD3 PTEDD2 PTEDD1 PTEDD0
Write:
Reset: 0
0
0
0
0
0
0
0
Figure 8-10 Port E Registers
PTEDn — Port E Data Register Bit n (n = 0–7)
For port E pins that are inputs, reads return the logic level on the pin. For port E pins that are configured
as outputs, reads return the last value written to this register.
Writes are latched into all bits of this register. For port E pins that are configured as outputs, the logic
level is driven out the corresponding MCU pin.
Reset forces PTED to all 0s, but these 0s are not driven out the corresponding pins because reset also
configures all port pins as high-impedance inputs with pullups disabled.
PTEPEn — Pullup Enable for Port E Bit n (n = 0–7)
For port E pins that are inputs, these read/write control bits determine whether internal pullup devices
are enabled. For port E pins that are configured as outputs, these bits are ignored and the internal pullup
devices are disabled.
1 = Internal pullup device enabled.
0 = Internal pullup device disabled.
PTEDDn — Data Direction for Port E Bit n (n = 0–7)
These read/write bits control the direction of port E pins and what is read for PTED reads.
1 = Output driver enabled for port E bit n and PTED reads return the contents of PTEDn.
0 = Input (output driver disabled) and reads return the pin value.
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MC9S08RC/RD/RE/RG
Freescale Semiconductor