MCMC68HC05L16 Freescale Semiconductor, Inc, MCMC68HC05L16 Datasheet - Page 31

• Manufacturer Part Number: MCMC68HC05L16
• Description: M68hc05 Microcontrollers
• Manufacturer: Freescale Semiconductor, Inc

2.4.1 Resistor Control Register 1
Bits 7–4 — Reserved
RBH — Port B Pullup Resistor (H)
RBL — Port B Pullup Resistor (L)
RAH — Port A Pullup Resistor (H)
RAL — Port A Pullup Resistor (L)
2.4.2 Resistor Control Register 2
RCx — Port C Pullup Resistor (Bitx)
Freescale Semiconductor
These bits are not used and always read as logic 0.
When this bit is set, pullup resistors are connected to the upper four bits of port B. This bit is cleared
on reset.
When this bit is set, pullup resistors are connected to the lower four bits of port B. This bit is cleared
on reset.
When this bit is set, pullup resistors are connected to the upper four bits of port A. This bit is cleared
on reset.
When this bit is set, pullup resistors are connected to the lower four bits of port A. This bit is cleared
on reset.
When RCx bit is set, the pullup resistor is connected to the corresponding bit of port C. This bit is
cleared on reset.
Address:
Address:
Reset:
Reset:
Read:
Read:
Write:
Write:
Option Map — $0008
Option Map — $0009
Bit 7
Bit 7
RC7
0
0
0
Figure 2-5. Resistor Control Register 1 (RCR1)
Figure 2-6. Resistor Control Register 2 (RCR2)
MC68HC05L16 • MC68HC705L16 Data Sheet, Rev. 4.1
RC6
6
0
0
6
0
RC5
5
0
0
5
0
RC4
4
0
0
4
0
RBH
RC3
3
0
3
0
RC1
RBL
2
0
2
0
Option Map for I/O Configurations
RAH
RC1
1
0
1
0
Bit 0
RAL
Bit 0
RC0
0
0
31