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IA80C152
Preliminary Data Sheet
UNIVERSAL COMMUNICATIONS CONTROLLER
IDA - If IDA is set to 1 then the destination address is automatically incremented after the transfer of each byte.
DAS
IDA
Destination
Auto-Increment
0
0
1
1
0
1
0
1
External Ram
External Ram
SFR
NO
YES
NO
YES
Internal RAM
SAS - This bit in conjunction with ISA determine the source address space.
ISA - If ISA is set to 1 then the source address is automatically incremented after the transfer of each byte.
SAS
ISA
0
1
0
1
Source
External Ram
External Ram
SFR
Auto-Increment
0
0
1
1
NO
YES
NO
YES
Internal RAM
DM - If this bit is set to a 1 then the DMA channel operates in demand mode. In this mode the DMA is initiated by
either an external signal or by a serial port flag depending on the value of the TM bit. If the DM bit is set to a 0 then
DMA is initiated by setting the GO bit.
TM - If DM is 1 then TM selects if DMA is initiated by an external signal (TM=1) or by a serial port bit (TM=0). If
DM is 0 then TM selects whether DMA transfers are in burst mode (TM=1) or in alternate cycles mode (TM=0).
DM
0
TM
0
Mode
Alternate Cycles
0
1
Burst
1
1
0
1
Serial Port Demand
External Demand
DONE - This bit indicates that the DMA operation has completed. It also causes an interrupt. This bit is set to 1
when BCRn equals 0 and is set to 0 when the interrupt is vectored to. The user can also set and clear this bit.
GO - If this bit is set to 1 it enables the DMA channel.
DPL, DPH (082h, 083h) - DPTR, or the "data pointer" consists of the two 8-bit registers, DPL and DPH. The DPTR
must be used for accesses to external memory requiring 16-bit addresses.
GMOD (084h) - An 8-bit register that controls the GSC Modes as described below.
7
6
5
4
3
2
1
0
XTCLK
M1
M0
AL
CT
PL1
PL0
PR
PR - If set to a 1 the GSC is in SDLC mode. If set to a 0 the GSC is in CSMA/CD mode.
PL0,1 - Preamble length:
PL1
PL0
Preamble length in bits
0
0
1
1
0
1
0
1
0
8
32
64
The length noted in the table includes the two bit BOF in CSMA/CD mode but not the SDLC flag. Zero length
preamble is not compatible with CSMA/CD mode.
CT - This bit determines the CRC type used. If set to a 1 the 32 bit AUTODIN II-32 is used. If set to a 0 the 16 bit
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innovASIC
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