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???
01/31/07 11:25
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Msg Score: +1
 +1 Good Answer/Helpful		 #131777 - CPOL = 0, CPHA = 0
Responding to: ???'s previous message
Hi Robert,

From your first post,
anl spcon, #0F7h ;cpol = 1 (?? maybe cpol= 0)
orl spcon, #04h ;cpha = 1

CPOL = 0, CPHA = 0 is good for MAX6957.

See this figure of MAX6957 datasheet
"Figure 5. 16-Bit Write Transmission to the MAX6957" (MAX6957.pdf p9)
- SCLK is held '0' just before the first SCLK - CPOL = 0
- MAX6957 fetches DIN at the first edge of SCLK - CPHA = 0

From the trace of your post, CPOL is already set to '0', but CPHA seems to be '1'.

Tsuneo

List of 48 messages in thread
TopicAuthorDate
Interfacing AT89C51ED2 to MAX6957 via SPI            01/01/70 00:00      
   a quick look            01/01/70 00:00      
      A bit hidden I know...            01/01/70 00:00      
   just a hint...            01/01/70 00:00      
      Thanks Jan            01/01/70 00:00      
      I know this is an Atmel chip, but            01/01/70 00:00      
         not that type of error            01/01/70 00:00      
   Light at the end of the tunnel...            01/01/70 00:00      
      Some scope traces...            01/01/70 00:00      
         CPOL = 0, CPHA = 0            01/01/70 00:00      
            Excellent.            01/01/70 00:00      
               What is the current problem?            01/01/70 00:00      
                  Thanks            01/01/70 00:00      
                     Next time...            01/01/70 00:00      
                        smiling            01/01/70 00:00      
                     this is what I was about to ask...            01/01/70 00:00      
                        a simple SPI 'test'            01/01/70 00:00      
                        MISO            01/01/70 00:00      
                           have you tried            01/01/70 00:00      
                              Good plan            01/01/70 00:00      
                                 Eureka            01/01/70 00:00      
                                    That's good...            01/01/70 00:00      
                                       true SPI and non-SPI driven by SPI            01/01/70 00:00      
                                          TRUE SPI chip?            01/01/70 00:00      
                                             OK            01/01/70 00:00      
                                    good choice            01/01/70 00:00      
                                       I used such...            01/01/70 00:00      
                                    Full code for reference if anyone's interested            01/01/70 00:00      
                           where did you measure?            01/01/70 00:00      
                           soldering iron...            01/01/70 00:00      
                              proto and prod            01/01/70 00:00      
                                 ah so...            01/01/70 00:00      
                                    HUH            01/01/70 00:00      
                                       now I really don\'t understand            01/01/70 00:00      
                                          well, let me try again            01/01/70 00:00      
                                             Oh I see...            01/01/70 00:00      
                                                try asking the person that does my layouts            01/01/70 00:00      
                                                Layout tool?            01/01/70 00:00      
                                                   tool... yes maybe, but for X1/X2???            01/01/70 00:00      
                                                      Just curious...            01/01/70 00:00      
                                                         huh...            01/01/70 00:00      
                                                   DXP            01/01/70 00:00      
                                                      Let's move to chat? (off-topic)            01/01/70 00:00      
                        The problem lies on MAX6957            01/01/70 00:00      
   I am happy for you            01/01/70 00:00      
      Thanks Erik            01/01/70 00:00      
      waitaminute...            01/01/70 00:00      
         comments            01/01/70 00:00      

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