Date: Mon, 07 Sep 1998 11:40:59 +0100 From: Roger Hardiman <roger@cs.strath.ac.uk> To: freebsd-alpha@FreeBSD.ORG Subject: Bt848 driver for Alpha Message-ID: <35F3B83B.167E@cs.strath.ac.uk>
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Hi, A question on porting the bt848 driver to Alpha hardware. Anyway, there are 2 32bit dependent sections a) memory mapped registers in the bt848 chip b) RISC code Q) The driver maps the registers (of which the bt848/878 has around 30) into the memory space and then writes to the registers as if you were writing to a normal variable (crude example bt848->register1 = some_value; bt848->register2 = some_value; Question: Can I write to just a 32 bit register with the Alpha. (in the same memory mapped way) Or, does the Alpha sneakilly do a 32 bit read of address n+1 and then do a 64 bit write. (think some old Alpha chips did this) I do not want to go writing to registers I was not intending to write to. Roger Hardiman Strathclyde Uni Telepresence Group To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-alpha" in the body of the message
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