TWI SHORTS not working

Question

Device: nRF51822 Rev G0 
 SDK: v5.2.0 
 Code: raw.githubusercontent.com/.../twi_hw_master.c 
 Basically, the TWI driver which uses PPI channels (sd_ppi_*) works perfectly - however, the driver which utilises the newly fixed (in Rev G0 devices) shortcuts DOES NOT. 
 I've narrowed down the issue to TWI read transactions only (writes seem to work fine) - see attached screenshot. 
 Has this new code been tested by Nordic with READ transactions? I only ask as the supplied example ( github.com/.../twi-display-5.1.0) only seems to issues writes to the LCD device. 
 Many thanks.

Nick · Accepted Answer

After some more testing, it seems like TWI SHORTS are indeed non-functional (even though they are supposed to be fixed in Chip Revision G0). 
 As a test, I took the latest Nordic code with SHORTS ( raw.githubusercontent.com/.../twi_hw_master.c) and replaced all SHORT code with the PPI equivalents and all TWI transactions work fine . Attached: [ sd_twi_hw_master.c ] 
 I believe this requires further investigation by Nordic. 
 Also, has anyone successfully got TWI SHORTS working? (i.e. TWI reads) 
 EDIT: 
 Shortcuts must be disabled before the twi_master_read() function returns. 
 Therefore, adding "NRF_TWI1->SHORTS = 0;" right before the function returns true fixes the issue completely! 
 (Thanks goes to RK for pointing me in the right direction).

TWI SHORTS not working

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