arrayForth notes #6 - Improved PCF2123 SPI Code

There were a lot of errors in the note #4 listing. I made the post mainly because I was excited to see commands fly between the PCF2123 and GA144 as viewed by a logic analyzer (even though spir8 didn't really work correctly). So, here is where I clean up the code, refactor it a bit and offer something a little more functional. I could go on for pages the rationale I had behind why this code lives in Node 7 and 8 and how I hooked up the chip. But, that is for another time. I hate having broken code posted to my blog, so this post is mainly a means to offer something that works. BTW, this runs on the eval board target chip. It still has some inefficiencies (compared to the GreenArray supplied SPI code), but by doing this myself (essentially a "clean room" implementation), I got to learn a lot more about how to code the GA144.

this is a brutally simple interface for a spi cr pin 1 - chip select cr pin 3 - clock cr pin 5 - mosi cr pin 17 - miso cr cr /spi call first. main loop . ckwait pauses for an effective rate of 2mhz cr -ckwait asserts the clock line low for 2mhz cr cs asserts the chip select line high cr -cs asserts the chip select line low cr		850 list todd's simple spi code cr 8 node 0 org cr /spi @ push ex . /spi ; ckwait 02 4A for unext ; approx. 2mhz cr -ckwait 05 2B !b ckwait ; cs 07 io b! -ckwait ; -cs 0A 29 !b ; spiw1 0C if drop 10 then 2F or !b ckwait -ckwa it ; spiw8 13 b- 80 7 for over over and spiw1 2/ ne xt drop drop ; spir1 1A -b @b . -if drop - 2* - ; then drop 2 * ; spir8 1E -b 0 7 for 0 spiw1 spir1 next 2/ ; cr 26
nxp pcf2123 calendar clock module. /pcf2123 initializes the pcf2123 clock cr rdt reads date and time sdt sets data and time port the cr		852 list 7 node 0 org cr /cs 00 left a! @p .. cs ! ; cs/ 04 @p .. -cs ! ; put 07 d- @p .. @p .. ! ! ; get 0A -d @p .. !p .. ! @ ; spiw 0D put @p .. spiw8 ! ; spir 11 @p .. spir8 ! get ; /pcf2123 14 @p .. /spi ! /cs 10 spiw 58 spiw c s/ ; rdt 1C -smhwdmy /cs 92 spiw spir spir spir spi r spir spir spir cs/ ; sdt 27 ymdwhms- /cs 12 spiw spiw spiw spiw spi w spiw spiw spiw cs/ ; testdate 32 12 11 10 9 8 7 6 sdt ; cr 3C