This and several other FBI registers are WRITE only - so you can write to them but cannot read the value back. The Programmer's Ref. Manual indicates them as WRITE only. -----Original Message----- From: Didier CONTIS [mailto:didier@ece.gatech.edu] Sent: Friday, May 04, 2001 4:16 PM To: IXP1200@CS.Princeton.EDU Subject: [ixp1200] Question about the Linux kernel and the FBI RDYBUS registers. -----BEGIN PGP SIGNED MESSAGE----- Hash: SHA1 Hi, I am observing a weird behavior when trying to read / write some registers from the Linux kernel running on the StrongARM. Basically, it seems I can write some registers like IREG without any problem from the StrongARM. However it seems I cannot with RDYBUS_TEMPLATE_CTL. However both registers are described in the doc as being r/w accessible by the StrongARM. Below is the output of my program. I am using the following definition for RDYBUS_TEMPLATE_CTL (IREG being already defined in the includes files): #define MY_RDYBUS_TEMPLATE_CTL IXP1200_REG(MICROENGINE_FBI_BASE+0x40180) [root@thing1 Didier]$./set_rcv Initial value of RDYBUS_TEMPLATE_CTL Register: 0 Initial value of IREG Register: 0 Address of RDYBUS_TEMPLATE_CTL Register: f0640180 Address of IREG Register: f06401e0 New value of RDYBUS_TEMPLATE_CTL Register: 0 New value of IREG Register: 80000000 Thanks in advance for any help. Regards, Didier. -----BEGIN PGP SIGNATURE----- Version: PGPfreeware 6.5.3 for non-commercial use http://www.pgp.com iQA/AwUBOvMOAHqEbTtUcuwQEQIARACeIhs42jMRRCCpV/1n4zKktqZenyQAoKKp 1KiT9hDkijWgnLVYRmz1B/g4 =sb4r -----END PGP SIGNATURE-----