PC Elite Reference
Technical Details
comprehensive group allowing full control of the IEEE bus. The
PC Elite have complete controller capabilities and also
implements the full range of talker, listener, serial and parallel
poll, service request, and remote programming functions.
NEC 7210 Register Map.
______________________
The heart of the ELITE card is the NEC 7210 GPIB
controller chip which chip has 16 registers, 8 read and 8 write.
The address mapping of these registers is not straight forward.
In PC2 mode, the 7210 register select lines rs0, rs1, rs2 are
connected to the computers address lines A0, A1 and A2. So the
7210 registers occupy 8 consecutive addresses. Thus with a base
address of 02B8h the registers occupy the eight addresses 02B8-
02BF hex.
In PC2a mode, the 7210 register select lines rs0, rs1, rs2 are
connected to the computers address lines A10, A11 and A12. So
instead of the registers occupying 8 consecutive addresses each
register is 0400hex apart.
Therefore, if the base address of the card is = 02E1Hex then the
7210 chip registers are as given in Figure 3-2.
Figure 3-2. PC2a Mode NEC 7210 Register Map.
__________________________________________
Read Register
Address
Function
_____________
_______
________
Reg0
02E1H
Data In register
Reg1
06E1H
Interrupt Status 1 Register
Reg2
0AE1H
Interrupt Status 2 Register
Reg3
0EE1H
Serial Poll Status Register
Reg4
12E1H
Address Status Register
Reg5
16E1H
Command Pass Through Register
Reg6
1AE1H
Address 0 Register
Reg7
1EE1H
Address 1 Register
Write Register
Address
Function
______________
_______
________
Reg0
02E1H
Data Out register
Reg1
06E1H
Interrupt Mask 1 Register
Reg2
0AE1H
Interrupt Mask 2 Register
3-26
Chapter 3
