COM20022I3V-HD SMSC, COM20022I3V-HD Datasheet - Page 44

• Manufacturer Part Number: COM20022I3V-HD
• Description: Network Controller & Processor ICs ARCNET Contrllr
• Manufacturer: SMSC

Specifications of COM20022I3V-HD

• Data Rate: 10 Mbps
• Supply Voltage (max): 3.465 V
• Supply Voltage (min): 3.135 V
• Maximum Operating Temperature: + 85 C
• Minimum Operating Temperature: - 40 C
• Mounting Style: SMD/SMT
• Package / Case: TQFP-48
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

Revision 02-27-06
BIT
BIT
1,0
7
6
5
4
16 Bit Access
Reserved
Internal Terminal
Counter Enable;
Re-Trigger mode
Terminal Count
Bit 8
Refresh
Synchronous
Gate Time
Reconfiguration
Timer 1, 0
BIT NAME
BIT NAME
W16
ITCEN/
RTRG
TC8/
RSYN/
GTTM
RCNTM1,
0
SYMBOL
SYMBOL
Table 6.14 - Bus Control Register
DATASHEET
This bit is used to Disable/Enable the 16 bit access. It
influences both CPU cycle and DMA cycle. W16= 0: Disable
(Default); W16= 1: Enable
This bit is undefined.
The function of this bit is mode dependent. ITCEN is for Non-
Burst or Burst mode. RTRG is for the two Programmable-
Burst modes.
ITCEN = 0: Terminate the DMA only by External TC. ITCEN
= 1: Terminate the DMA by Internal or External TC.
RTRG = 0: External Re-Trigger mode; Negated DREQ pin is
Re-asserted by falling edge of nREFEX pin. RTRG = 1:
Internal Re-Trigger mode; Negated DREQ pin is Re-asserted
by timeout of internal gate timer (350ns/750ns).
The function of this bit is mode dependent. TC8 is for Non-
burst or burst mode. RSYN and GTTM are for the two
Programmable-Burst modes. RSYN is for External Re-
Trigger mode. GTTM is for internal Re-Trigger mode.
Non-burst or burst mode:
TC8: Bit 8 (MSB) of 9 bit Terminal Count setting register.
The other 8 bits are in the DMA Count register. Terminal
Count setting register is ignored when ITCEN = 0.
Programmable-Burst and External Re-Trigger mode:
RSYN = 0: DMA is started Immediately.
RSYN = 1: DMA is started after Refresh execution.
Programmable-Burst and Internal Re-Trigger mode:
GTTM = 0: Gate Time is 350nS (min)
GTTM = 1: Gate Time is 750nS (min)
These bits are used to program the reconfiguration timer as
a function of maximum node count. These bits set the time
out period of the reconfiguration timer as shown below. The
time out periods shown are for 10 Mbps.
Note*: The node ID value 255 must exist in the network for
RCNTM1
0
0
1
1
Page 44
13.125 mS timeout to be valid.
RCNTM0
10 Mbps ARCNET (ANSI 878.1) Controller with 2Kx8 On-Board RAM
0
1
0
1
DESCRIPTION
DESCRIPTION
13.125 mS*
26.25 mS
Time Out
52.5 mS
210 mS
Period
Up to 255 nodes
Up to 64 nodes
Up to 32 nodes
Up to 16 nodes
Max Node Count
SMSC COM20022I 3V
Datasheet