MC68HC05C9A Datasheet, PDF (23/124 Pages) Freescale Semiconductor, Inc – Microcontrollers

I/O Registers
2.5 I/O Registers
Except for the option register, all I/O, control and status registers are located within one 32-byte block in
page zero of the address space ($0000–$001F). A summary of these registers is shown in Figure 2-2.
More detail about the contents of these registers is given in Figure 2-3.
Address
$0000
$0001
Register Name
Port A Data Register
Port B Data Register
$0002
$0003
$0004
Port C Data Register
Port D Data Register
Port A Data Direction Register
$0005
$0006
$0007
Port B Data Direction Register
Port C Data Direction Register
Port D Data Direction Register
$0008
$0009
$000A
Unused
Unused
Serial Peripheral Control Register
$000B
$000C
$000D
Serial Peripheral Status Register
Serial Peripheral Data Register
Baud Rate Register
$000E
$000F
$0010
Serial Communications Control Register 1
Serial Communications Control Register 2
Serial Communications Status Register
$0011
$0012
$0013
Serial Communications Data Register
Timer Control Register
Timer Status Register
$0014
$0015
$0016
Input Capture Register High
Input Capture Register Low
Output Compare Register High
$0017
$0018
$0019
Output Compare Register Low
Timer Register High
Timer Register Low
$001A
$001B
$001C
Alternate Timer Register High
Alternate Timer Register Low
Unused
$001D
$001E
$001F
COP Reset Register
COP Control Register
Reserved
Figure 2-2. I/O Register Summary
MC68HC05C9A Advance Information Data Sheet, Rev. 5.1
Freescale Semiconductor
23