minor doc updates

diff --git a/python-lib/usbio.py b/python-lib/usbio.py
index f0fef97fec3f7ecd8b5e632ff8a3da907f613346..f589646a0e9ee10d090ff7d7e8116ab6ef986e21 100644 (file)
--- a/python-lib/usbio.py
+++ b/python-lib/usbio.py
@@ -25,7 +25,7 @@ from myhdl import bin as b
 #
 #           OTA-A
 #           31 - cintA
-#           30 - zeroA 
+#           30 - zeroA
 #           29 - seA
 #           28 - fastA
 #           27..16 - tuneA
@@ -156,7 +156,6 @@ class I2C(object):
         if ret < 0:
             raise FTDI_Error(self.ftdi.get_error_string(self.context))
 
-
     def _clear_scl(self):
         self.io[self.scl] = 1
         self.ftdi.set_bitmode(self.context, int(self.io), self.ftdi.BITMODE_BITBANG)
@@ -1114,6 +1113,7 @@ class Mux(object):
 
 
 class AD524x(object):
+    """Digitally-controlled potentiometer."""
     ADDR_BASE = intbv(0b0101100, max=2**7)
     SEL_POS = 7
     RS_POS = 6
@@ -1298,6 +1298,7 @@ class AD524x(object):
         return s
 
 class DAC8568(object):
+    """8-channel DAC."""
     CTL_WIDTH = 32
     DAC_WIDTH = 16
     #POR_VALUE = 2**(DAC_WIDTH - 1)
@@ -1419,13 +1420,14 @@ class DAC8568(object):
     def _feature(self, value):
         #self._word[4:0] = value #intbv(value, max=2**4)
         self._word += ((value & 0xf) << 0)#intbv(value, max=2**4)
-        
+
 
 class ADS8201_Error(Exception):
     pass
 
 class ADS8201(object):
-    """Configures and operates an ADS8201 over the given SPI bus."""
+    """Configures and operates an 8-channel ADC system, ADS8201 over the given
+    SPI bus."""
     # register addresses
     CH01_CCR = 0
     CH23_CCR = 1