From pier@positron.ps.uci.edu Wed Sep 2 02:26:50 1998 Date: Tue, 01 Sep 1998 10:14:10 -0700 From: Steve Pier To: "P.W.Phillips@rl.ac.uk" Cc: unno@post.kek.jp, FAHLAND@positron.ps.uci.edu, GARETH.MOORHEAD@cern.ch Subject: Re: TCC and abcdaq Peter and Tom: > process of reverse engineering (of ALDAS). The clock register was not > at all transparent at a first glance, and I had little success in > figuring out which bits to set for a given clock source/frequency. > Maybe if Steve or Tom can send me / post to the web a list of Indeed, the clock selection is under software control and a bit obscure. It must be specified when software initializes the TCC. I do not know if Tom's TCC-compatible DSP code allows the host to specify the clock source via a message. When the TCC's JP2 jumper is set to EXT, the software clock selection is ignored, and the external clock is used. Steve ---------------------------------------------------------- The file http://positron.ps.uci.edu/~pier/dsp_soft/tcc_pub.h contains: void Initialize_TCC( int ClockSource ); /* Initializes TCC hardware and driver */ /*** Constants ***/ /* Clock source constants: see Initialize_TCC(). */ /* Consult the TCC designer before using ckStopped or ckSoft. */ #define ckOscDiv2 0 /* osc/2 */ #define ckOscDiv4 1 /* osc/4 */ #define ckOscDiv8 2 /* osc/8 */ #define ckOscDiv16 3 /* osc/16 */ #define ckStopped 4 /* clock is stopped */ #define ckExternal 5 /* external clock */ #define ckOsc 6 /* osc (the TCC's on-board crystal oscillator) */ #define ckSoft 7 /* clock pulsed by software */