| Line 32... |
Line 32... |
-- "0_1111_1111" (0x0FF) TX Length / Status**
|
-- "0_1111_1111" (0x0FF) TX Length / Status**
|
--
|
--
|
-- Receive Memory Map
|
-- Receive Memory Map
|
-- "1_0000_0000" (0x100) RX Buffer START
|
-- "1_0000_0000" (0x100) RX Buffer START
|
-- "1_1111_1101" (0x1FD) RX Buffer END
|
-- "1_1111_1101" (0x1FD) RX Buffer END
|
-- "1_1111_1110" (0x0FE) Reserved
|
-- "1_1111_1110" (0x0FE) RX Checksum Status***
|
-- "1_1111_1111" (0x1FF) RX Length / Status***
|
-- "1_1111_1111" (0x1FF) RX Length Status****
|
--
|
--
|
-- * Address 0xFE reports the SDLC bit clock status and updates on changes.
|
-- * Address 0xFE reports the SDLC bit clock status and updates on changes.
|
-- 1) If BClk_Okay = '0' (Bitclock is NOT present), the field will report
|
-- 1) If BClk_Okay = '0' (Bitclock is NOT present), the field will report
|
-- 0x00. Otherwise, it will report 0xFF if the bitclock is present.
|
-- 0x00. Otherwise, it will report 0xFF if the bitclock is present.
|
-- 2) Writing any value to the register will cause the controller to
|
-- 2) Writing any value to the register will cause the controller to
|
| Line 48... |
Line 48... |
-- using the write value as the packet length.
|
-- using the write value as the packet length.
|
-- 2) Values 0x00, 0xFE, or 0xFF are invalid, and will be ignored.
|
-- 2) Values 0x00, 0xFE, or 0xFF are invalid, and will be ignored.
|
-- 3) This value will change from the user written value to 0xFF once the
|
-- 3) This value will change from the user written value to 0xFF once the
|
-- packet is transmitted to indicate the transmission is complete.
|
-- packet is transmitted to indicate the transmission is complete.
|
--
|
--
|
-- *** This location serves as the status register for the receive
|
-- *** This location serves as the status register for receive checksum test
|
|
-- 1) A value of 0x00 indicates the CRC did NOT match, while a value
|
|
-- of 0xFF indicates that the recieved CRC matches the calculated CRC.
|
|
--
|
|
-- **** This location serves as the status register for the receive
|
-- 1) This value is only updated on reception of a full frame, indicated
|
-- 1) This value is only updated on reception of a full frame, indicated
|
-- by a start followed by a stop flag. Incomplete frames are ignored.
|
-- by a start followed by a stop flag. Incomplete frames are ignored.
|
-- 2) If the packet CRC matches the transmitted CRC, the packet is
|
-- 2) If the packet CRC matches the transmitted CRC, the packet is
|
-- considered valid, and the received length (less CRC) is written.
|
-- considered valid, and the received length (less CRC) is written.
|
-- 3) If the packet CRC doesn't match, a value of ERR_CHECKSUM is written.
|
-- 3) If the packet CRC doesn't match, a value of ERR_CHECKSUM is written.
|
