Texas Instruments C28 Series Student Guide

External Interface (XINTF)
XINTF Registers
XINTF Registers
(lab file: Xintf.c)
(lab file: Xintf.c)
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XTIMINGx
XTIMINGx
specifies read (lead, active, trail), write
specifies read (lead, active, trail), write
(lead, active, trail), X2TIMING, and use XREADY
(lead, active, trail), X2TIMING, and use XREADY
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XINTCNF2
XINTCNF2
selects fundamental clock XTIMCLK (for
selects fundamental clock XTIMCLK (for
lead, active, trail), CLKMODE and CLKOFF
lead, active, trail), CLKMODE and CLKOFF
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XBANK
XBANK
specifies the number of XTIMCLK cycles to
specifies the number of XTIMCLK cycles to
add between two specified zone (bank switching)
add between two specified zone (bank switching)
Name
Name
Address
Address
Size (x16) Description
Size (x16) Description
XTIMING0
XTIMING0
0x00 0B20
0x00 0B20
2
2
XINTF Zone 0 Timing Register
XINTF Zone 0 Timing Register
XTIMING1
XTIMING1
0x00 0B22
0x00 0B22
2
2
XINTF Zone 1 Timing Register
XINTF Zone 1 Timing Register
XTIMING2
XTIMING2
0x00 0B24
0x00 0B24
2 XINTF Zone 2 Timing Register
2 XINTF Zone 2 Timing Register
XTIMING6
XTIMING6
0x00 0B2C
0x00 0B2C
2
2
XINTF Zone 6 Timing Register
XINTF Zone 6 Timing Register
XTIMING7
XTIMING7
0x00 0B2E
0x00 0B2E
2
2
XINTF Zone 7 Timing Register
XINTF Zone 7 Timing Register
XINTCNF2
XINTCNF2
0x00 0B34
0x00 0B34
2
2
XINTF Configuration Register
XINTF Configuration Register
XBANK
XBANK
0x00 0B38
0x00 0B38
2
2
XINTF Bank Control Register
XINTF Bank Control Register
Configuring XINTF with Header Files
Configuring XINTF with Header Files
XintfRegs.XTIMING0.bit.XWRLEAD = 1;
XintfRegs.XTIMING0.bit.XWRLEAD = 1;
XintfRegs.XTIMING0.bit.XWRACTIVE = 2;
XintfRegs.XTIMING0.bit.XWRACTIVE = 2;
XintfRegs.XTIMING0.bit.XWRTRAIL = 0;
XintfRegs.XTIMING0.bit.XWRTRAIL = 0;
XintfRegs.XTIMING0.bit.XRDLEAD = 1;
XintfRegs.XTIMING0.bit.XRDLEAD = 1;
XintfRegs.XTIMING0.bit.XRDACTIVE = 3;
XintfRegs.XTIMING0.bit.XRDACTIVE = 3;
XintfRegs.XTIMING0.bit.XRDTRAIL = 1;
XintfRegs.XTIMING0.bit.XRDTRAIL = 1;
Zone write and read timing example:
Zone write and read timing example:
XintfRegs.XBANK.bit.BANK = 7;
XintfRegs.XBANK.bit.BANK = 7;
XintfRegs.XBANK.bit.BCYC = 3;
XintfRegs.XBANK.bit.BCYC = 3;
Bank switching example:
Bank switching example:
Suppose the external device in zone 7 is slow
Suppose the external device in zone 7 is slow
getting off the bus; Add 3 additional cycles when switching fro
getting off the bus; Add 3 additional cycles when switching fro
m zone 7 to
m zone 7 to
another zone to avoid bus contention
another zone to avoid bus contention
XintfRegs.XINTCNF2.bit.XTIMCLK = 1;
XintfRegs.XINTCNF2.bit.XTIMCLK = 1;
// XTIMCLK = SYSCLKOUT/2
// XTIMCLK = SYSCLKOUT/2
XintfRegs.XINTCNF2.bit.CLKOFF = 0;
XintfRegs.XINTCNF2.bit.CLKOFF = 0;
// XCLKOUT is enabled
// XCLKOUT is enabled
XintfRegs.XINTCNF2.bit.CLKMODE = 1;
XintfRegs.XINTCNF2.bit.CLKMODE = 1;
// XCLKOUT = XTIMCLK/2
// XCLKOUT = XTIMCLK/2
XINTCNF2 example:
XINTCNF2 example:
Timing for all zones based on XTIMCLK = SYSCLKOUT/2
Timing for all zones based on XTIMCLK = SYSCLKOUT/2
C28x - System Design 10 - 9

Texas Instruments C28 Series Specifications

General

Brand	Texas Instruments
Model	C28 Series
Category	Computer Hardware
Language	English