9-2
General Purpose Timers
9.1.2 Programmability
The GPT is fully programmable through memory mapped registers. Programmability features include:
• Programmable time base register (sets the Time Base Counter)
• Maskable time-base comparison support for each compare timer
• Programmable compare timer values
• Enable/disable control of all capture timers
• Enable/disable control of all capture and compare interrupts
• Mask control of interrupt status bits
• Programmable capture event edge detection and synchronization
9.2 Mode of Operation
9.2.1 Time Base Counter
The GPT time-base is provided by the 32-bit Time Base Counter (TBC) register. The TBC continually incre-
ments once every CPC700 SYS_CLOCK unless written or reset. The TBC provides the reference time for
all capture and compare timers. When the TBC is at its maximum value (all bits set to 1) it will roll back to
zero upon the next clock. The TBC may be read and written by software using its memory mapped
address.
The TBC is synchronously reset to zero upon a CPC700 reset or when either the GPT_RST or
GPT_TBC_RST bits are set in the CPRRESET register. Refer to Section 6.5.2, “Peripheral Reset Control
Register (CPRRESET)” for details.
FF65_0088
GPTCOMP2
GPT Compare Timer 2
R/W
32
FF65_008C
GPTCOMP3
GPT Compare Timer 3
R/W
32
FF65_0090
GPTCOMP4
GPT Compare Timer 4
R/W
32
FF65_0094 -
FF65_00BC
(Reserved)
FF65_00C0
GPTMASK0
Compare Mask (Compare Timer 0)
R/W
32
FF65_00C4
GPTMASK1
Compare Mask (Compare Timer 1)
R/W
32
FF65_00C8
GPTMASK2
Compare Mask (Compare Timer 2)
R/W
32
FF65_00CC
GPTMASK3
Compare Mask (Compare Timer 3)
R/W
32
FF65_00D0
GPTMASK4
Compare Mask (Compare Timer 4)
R/W
32
FF65_00D4 -
FF65_00FC
(Reserved)
FF50_9080
CPRCAPTEVNT
GPT Capture Event Generation
R/W
32
Table 96. GPT Registers (Continued)
Base Address
Register
Register Name
Access
Mode
Width
(bits)
Summary of Contents for CPC700
Page 10: ...Table of Contents x Table of Contents...
Page 16: ...Tables xvi List of Tables...
Page 28: ...1 12 CPC700 User s Manual Preliminary...
Page 72: ...3 36 Processor Interface...
Page 132: ...4 60 Memory Controller...
Page 184: ...5 52 PCI Interface...
Page 194: ...6 10 Clock Power Management and Reset...
Page 224: ...8 18 IIC...
Page 244: ...10 10 Interrupt Controller...
Page 246: ...I 11 2 JTAG...
Page 250: ...12 4 Processor Local Bus PLB...
Page 262: ...14 10 Register Summary...
Page 267: ...CPC700 User s Manual Preliminary...