no scc_hdlc struct in commproc.h

Hello,
I did not find a scc_hdlc structure like scc_enet and scc_uart in
commproc.h. Do I just need to make one similar to scc_enet and modify it
according to p.24-4 in the 860 book? This is the scc parameter ram memory
map versus scc ethernet parameter ram memmory map.
Thank you in advance.
--Julia

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Julia Elbert wrote:

I did not find a scc_hdlc structure like scc_enet and scc_uart in
commproc.h.

I don't think anyone has submitted any source patches to provide it.
There has been some discussion in the past......

.... Do I just need to make one similar to scc_enet and modify it
according to p.24-4 in the 860 book?

That would be great.  If you would like to submit it as a patch someday,
that would be even greater :-).  What are you connecting at each end
of the port?  NMSI, TDM, custom software?

Another part of your project will be writing a driver.  In the past,
the accepted suggestion was to not modify the uart driver, as that
is a _uart_ driver, not an SCC driver.  You can use that as a model
to create, say, hdlc.c......Then just ensure you don't try to configure
the SCC in both places (and there  may need to be a little knowledge
about each one in every driver).

Thank you in advance.

Have fun!


	-- Dan

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Hello Julia,

I did not find a scc_hdlc structure like scc_enet and scc_uart in
commproc.h.

I wrote the following one for my project (which is about adding ISDN
functionality for MPC860):

/*********   SCC parameter RAM for HDLC mode   *********/
typedef struct scc_hdlc {
	ushort	scc_rbase;	// Rx Buffer descriptor base address
	ushort	scc_tbase;	// Tx Buffer descriptor base address
	u_char	scc_rfcr;	// Rx function code
	u_char	scc_tfcr;	// Tx function code
	ushort	scc_mrblr;	// Max receive buffer length
	uint	scc_rstate;	// internal
	uint	scc_idp;	// internal
	ushort	scc_rbptr;	// internal
	ushort	scc_ibc;	// internal
	uint	scc_rxtmp;	// internal
	uint	scc_tstate;	// internal
	uint	scc_tdp;	// internal
	ushort	scc_tbptr;	// internal
	ushort	scc_tbc;	// internal
	uint	scc_txtmp;	// internal
	uint	scc_rcrc;	// internal
	uint	scc_tcrc;	// internal
	// here begins HDLC specific part
	uint	scc_res1;	// reserved
	uint	scc_cmask;	// CRC mask
	uint	scc_cpres;	// CRC preset
	ushort	scc_disfc;	// discarded frame counter
	ushort	scc_crcec;	// CRC error counter
	ushort	scc_abtsc;	// abort sequence counter
	ushort	scc_nmarc;	// nonmatching address receive counter
	ushort	scc_retrc;	// frame retransmission counter
	ushort	scc_mflr;	// Max frame length register
	ushort	scc_maxcnt;	// internal
	ushort	scc_rfthr;	// recceived frames threshold
	ushort	scc_rfcnt;	// internal
	ushort	scc_hmask;	// HDLC address mask register
	ushort	scc_haddr1;	// HDLC address register 1
	ushort	scc_haddr2;	// HDLC address register 2
	ushort	scc_haddr3;	// HDLC address register 3
	ushort	scc_haddr4;	// HDLC address register 4
	ushort	scc_tmp;	// internal
	ushort	scc_tmp_mb;	// internal
} scc_hdlc_t;

Ciao - Tobias


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Tobias Otto-Adamczak wrote:

/*********   SCC parameter RAM for HDLC mode   *********/

Just a couple of minor comments......

typedef struct scc_hdlc {

        ushort  scc_rbase;      // Rx Buffer descriptor base address
        ushort  scc_tbase;      // Tx Buffer descriptor base address
        u_char  scc_rfcr;       // Rx function code
        u_char  scc_tfcr;       // Tx function code
        ushort  scc_mrblr;      // Max receive buffer length
        uint    scc_rstate;     // internal
        uint    scc_idp;        // internal
        ushort  scc_rbptr;      // internal
        ushort  scc_ibc;        // internal
        uint    scc_rxtmp;      // internal
        uint    scc_tstate;     // internal
        uint    scc_tdp;        // internal
        ushort  scc_tbptr;      // internal
        ushort  scc_tbc;        // internal
        uint    scc_txtmp;      // internal
        uint    scc_rcrc;       // internal
        uint    scc_tcrc;       // internal

This first part of the object is defined by 'scc_param', so the
convention would have been:

typedef struct scc_hdlc {
	sccp_t	scc_hdlc;

Followed by:

        // here begins HDLC specific part
        uint    scc_res1;       // reserved

The documentation describes the CPM devices in this way, and it is
a little more clear what is common to the SCC, and what is unique
to the HDLC feature.

....since we aren't writing C++, I also dislike the '//' comment......

I would have made these two changes if it was sent as a patch to
me for inclusion in the source code.....

In fact, I will keep this and include it in the future....Do you have
any code you want to submit along with it?



	-- Dan

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