General Purpose Timer Module (GPT)
MCF52110 ColdFire® Integrated Microcontroller Reference Manual, Rev. 1
20-16
Freescale Semiconductor
Preliminary
20.6.18 GPT Port Data Register (GPTPORT)
20.6.19 GPT Port Data Direction Register (GPTDDR)
20.7
Functional Description
The general purpose timer (GPT) module is a 16-bit, 4-channel timer with input capture and output
compare functions and a pulse accumulator.
IPSBAR
Offset: 0x1A_001D (GPTPORT)
Access: Supervisor read/write
7
6
5
4
3
2
1
0
R
0
0
0
0
PORTT
W
Reset:
0
0
0
0
0
0
0
0
Figure 20-20. GPT Port Data Register (GPTPORT)
Table 20-21. GPTPORT Field Descriptions
Field
Description
7–4
Reserved, should be cleared.
3–0
PORTT
GPT port input capture/output compare data. Data written to GPTPORT is buffered and drives the pins only when
they are configured as general-purpose outputs.
Reading an input (DDR bit = 0) reads the pin state; reading an output (DDR bit = 1) reads the latched value. Writing
to a pin configured as a GPT output does not change the pin state. These bits are read anytime (read pin state when
corresponding PORTT
n
bit is 0, read pin driver state when corresponding GPTDDR bit is 1), write anytime.
IPSBAR
Offset: 0x1A_001E (GPTDDR)
Access: Supervisor read/write
7
6
5
4
3
2
1
0
R
0
0
0
0
DDRT
W
Reset:
0
0
0
0
0
0
0
0
Figure 20-21. GPT Port Data Direction Register (GPTDDR)
Table 20-22. GPTDDR Field Descriptions
Bit(s)
Name
Description
7–4
—
Reserved, should be cleared.
3–0
DDRT
Control the port logic of PORTT
n
. Reset clears the PORTT
n
data direction register,
configuring all GPT port pins as inputs. These bits are read anytime, write anytime.
1 Corresponding pin configured as output
0 Corresponding pin configured as input