Spectrum Digital TMS320C6416 DSK, Техническое описание

Страница: 18 / 53

Spectrum Digital, Inc
2-5
2.1.6 MISC Register
The MISC register is used to provide software control for miscellaneous board
functions. On the 6416 DSK, the MISC register controls how auxiliary signals are
brought out to the daughter-card connectors.
McBSP1 and McBSP2 are usually used as the control and data ports of the on-board
AIC23 codec. The power-on state of these bits (both 0s) represents that configuration.
Set MCBSP1SEL or MCBSP2SEL to route the McBSPs to the daughtercard
connectors rather than the codec.
The Flash and CPLD share CE1 which means that the highest address bit (A21) is
used to differentiate between the two. In this configuration 512Kbytes of 8-bit Flash are
visible at the beginning of CE1 which matches the chip on the production board. If the
Flash is replaced with a 1Mbyte chip, only 512Kbytes of Flash will still be visible but
FLASH_PAGE can be used to select between the top and bottom halves.
FLASH_PAGE replaces the address bit (A21) that is lost sharing CE1 with the CPLD.
An on-board PLL is used to generate the DSP’s input clock frequency. The
DSPPLL_SELECT and DSPPLL_ENABLE bits are read-only versions of the PLL
configuration signals. DSPPLL_ENABLE will read 1 if the PLL is enabled.
DSPPLL_SELECT (set by configuration switch #4) switches between a 50 Mhz and
60 Mhz input clock.
The 6416’s PCI interface and McBSP2 share some pins. The McBSP2_EN signal is
used to disable McBSP2 when the PCI interface is active. McBSP2_EN is generated
on the board when an appropriate daughtercard that uses PCI is plugged in, it can be
read through this CPLD bit.
The scratch bits are unused. They can be set to any value.
Table 5: MISC Register
Bit Name R/W Description
7 McBSP2_EN R Value of McBSP2_EN from PCI header
6 SCRATCH_4 R/W Scratch bit 4
5 SCRATCH_3 R/W Scratch bit 3
4 DSPPLL_SELECT R PLL select (0 = 50/600 Mhz, 1 = 60/720 Mhz)
3 DSPPLL_ENABLE R PLL enable (0 = off, 1 = on)
2 FLASH_PAGE R/W Flash address bit 19
1 MCBSP2SEL R/W McBSP2 on/off board (0 = on-board, 1 = off-board)
0 MCBSP1SEL R/W McBSP1 on/off board (0 = on-board, 1 = off-board)