Motorola MPC823e Reference Manual page 728

Communication Processor Module
16.9.19.8 SCCx ASYNC HDLC PARAMETER RAM MEMORY MAP. When configured as
an SCCx ASYNC HDLC controller, a serial communication controller overlays the structure
used in Table 16-24 with the SCCx ASYNC HDLC parameters described in Table 16-28.
Table 16-28. SCCx ASYNC HDLC Parameter RAM Memory Map
ADDRESS
SCCx Base+34
SCCx Base+38
SCCx Base+3C
SCCx Base+3E
SCCx Base+40
SCCx Base+42
SCCx Base+44
SCCx Base+46
SCCx Base+48
SCCx Base+4A
SCCx Base+4C
SCCx Base+4E
SCCx Base+50
SCCx Base+54
SCCx Base+58
SCCx Base+5A
NOTE: You are only responsible for initializing the items in bold.
SCCx Base = (IMMR & 0xFFFF0000) + 0x3D00 (SCC2 ) and 0x3E00 (SCC3).
• C_MASK—This value must be initialized with 0x0000F0B8.
• C_PRES—This value must be initialized with 0x0000FFFF.
• BOF—This value must be initialized to the beginning of the flag character (PPP is 0x7E
and IRLAP is 0xC0).
• EOF—This value must be initialized to the end of the flag character (PPP is 0x7E and
IrLAP is 0xC1).
• ESC—This value must be initialized to the control escape character (PPP is 0x 7D and
IrLAP is 0x7D).
• Reserved—These areas are temporary storage locations for the microcode. They must
not be initialized or modified.
• ZERO—You must set this field to zero.
• RFTHR—The received frames threshold indicates how many frames are received
before the RXF bit is set in the SCCE–ASYNC HDLC register.
16-274
NAME WIDTH
C_MASK Word
C_PRES Word
BOF Half-word
EOF Half-word
ESC Half-word
RES Half-word
RES Half-word
ZERO Half-word
RES Half-word
RFTHR Half-word
RES Half-word
RES Half-word
TXCTL_TBL Word
RXCTL_TBL Word
NOF Half-word
RES Half-word
MPC823e REFERENCE MANUAL
DESCRIPTION
CRC Constant
CRC Preset
Beginning Of Flag Character
End Of Flag Character
Control Escape Character
Reserved
Reserved
Reserved
Reserved
Received Frames Threshold
Reserved
Reserved
TX Control Character Mapping Table
RX Control Character Mapping Table
Number of Opening Flags
Reserved
MOTOROLA