Update README.md

README.md

@@ -3,12 +3,12 @@
 Functions and constants for declaring arrays in the flash memory 
 of an Arduino Nano 33 BLE and Arduino Nano 33 BLE Sense.
 
-The Nano 33 BLE uses a nRF52840 microcontroller chip
-The Flash on the nRF52840 has 256 pages of 1024 words, each word is 4 bytes.
-Each page is individually erasable; each word is individually writable.
+The Nano 33 BLE uses a nRF52840 microcontroller chip.  
+The Flash on the nRF52840 has 256 pages of 1024 words, each word is 4 bytes.  
+Each page is individually erasable; each word is individually writable.  
 
 This library defines 2 functions:  
-int flashErasePage(byte page);  
+<mono>int flashErasePage(byte page);</mono>  
 void flashMode(_flashModeEnum mode);  
 where mode is one of  
   FLASH_READONLY  
@@ -25,7 +25,9 @@ This code is most useful for implementing non-volatile arrays,
 particularly when the datatype is of the size of a flash word or larger
 (eg. int, long, float, double).  
 Arrays of datatypes smaller than a flash word (eg. char, byte, short)
-are awkward to implement, but doable.
+are awkward to implement, but doable.  
+The issue is that the nature of flash memory is such that each word 
+is writable essentially once after each erase.  
 
 Write data to a flash array with this motif:  
 flashMode(FLASH_WRITE);