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Refresh some Olimex LPC1766STK networking configurations

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This commit is contained in:
Gregory Nutt 2015-06-02 08:12:44 -06:00
parent 1d697a18d1
commit e6b8d2eebe
1 changed files with 2 additions and 45 deletions
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47
arch/arm/src/lpc17xx/lpc17_emacram.h
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@ -132,51 +132,8 @@
*
* 16384 <= ntx * (pktsize + 8 + 4) + nrx * (pktsize + 8 + 8)
*
* If ntx == nrx and pktsize == 424, then you could have
* ntx = nrx = 18.
*
* An example with all of the details:
*
* NTXDESC=18 NRXDESC=18 CONFIG_NET_EMACRAM_SIZE=16Kb CONFIG_NET_ETH_MTU=420:
* LPC17_TXDESCTAB_SIZE = 18*8 = 144
* LPC17_TXSTATTAB_SIZE = 18*4 = 72
* LPC17_TXTAB_SIZE = 216
*
* LPC17_RXDESCTAB_SIZE = 16*8 = 144
* LPC17_RXSTATTAB_SIZE = 16*8 = 144
* LPC17_TXTAB_SIZE = 288
*
* LPC17_DESCTAB_SIZE = 504
* LPC17_DESC_BASE = LPC17_SRAM_BANK0 + 0x00004000 - 504
* = LPC17_SRAM_BANK0 + 0x00003e08
* LPC17_TXDESC_BASE = LPC17_SRAM_BANK0 + 0x00003e08
* LPC17_TXSTAT_BASE = LPC17_SRAM_BANK0 + 0x00003e98
* LPC17_RXDESC_BASE = LPC17_SRAM_BANK0 + 0x00003ee0
* LPC17_RXSTAT_BASE = LPC17_SRAM_BANK0 + 0x00003f70
*
* LPC17_PKTMEM_BASE = LPC17_SRAM_BANK0
* LPC17_PKTMEM_SIZE = 0x00004000-504 = 0x00003e40
* LPC17_PKTMEM_END = LPC17_SRAM_BANK0 + 0x00003e08
* LPC17_MAXPACKET_SIZE = ((420 + 3 + 2) & ~3) = 424
* LPC17_NTXPKTS = 18
* LPC17_NRXPKTS = 18
* LPC17_TXBUFFER_SIZE = 18 * 424 = 0x00001dd0
* LPC17_RXBUFFER_SIZE = 18 * 424 = 0x00001dd0
* LPC17_BUFFER_SIZE = 0x00003ba0
* LPC17_BUFFER_BASE = LPC17_SRAM_BANK0
* LPC17_TXBUFFER_BASE = LPC17_SRAM_BANK0
* LPC17_RXBUFFER_BASE = LPC17_SRAM_BANK0 + 0x00001dd0
* LPC17_BUFFER_END = LPC17_SRAM_BANK0 + 0x00003ba0
*
* Then the check LPC17_BUFFER_END < LPC17_PKTMEM_END passes. The amount of
* unused memory is small: 0x00003e08-0x00003ba0 or about 616 bytes -- not
* enough for two more packets.
*
* [It is also possible, with some effort, to reclaim any unused
* SRAM for the use in the heap. But that has not yet been pursued.]
* If ntx == nrx and pktsize == 590, then you could have ntx = nrx = 13. In this
* case, you would need only 15,704 bytes of EMAC RAM (but be careful with alignment!).
*/
#define LPC17_TXDESCTAB_SIZE (CONFIG_NET_NTXDESC*LPC17_TXDESC_SIZE)