Z86L7208FSC datasheet(33/71 Pages) ZILOG

33 / 71 page

Z86C72/C92/L72/L92

Zilog

IR Microcontroller

DS97LVO0900

P R E L I M I N A R Y

6-33

port registers, 236 general-purpose registers, and 16 con-

trol and status registers (R0-R3, R4-R239, and R240-

R255, respectively), Plus two expanded registers groups

(Banks D and F). Instructions can access registers directly

or indirectly through an 8-bit address field. This allows a

short, 4-bit register address using the Register Pointer

(Figure 23). In the 4-bit mode, the register file is divided

into 16 working register groups, each occupying 16 contin-

uous locations. The Register Pointer addresses the start-

ing location of the active working register group.

Note: Working register group E0-EF can only be access-

ed through working registers and indirect addressing

modes.

Stack. The Z86L/CX2 external data memory or the inter-

nal register file is used for the stack. An 8-bit Stack Pointer

(R255) is used for the internal stack that resides in the gen-

eral-purpose registers (R4-R239). SPH is used as a gen-

eral-purpose register only when using internal stacks.

Note: When SPH is used as a general-purpose register

and Port 0 is in address mode, the contents of SPH will be

loaded into Port 0 whenever the internal stack is accessed.

Figure 20. Register Pointer

Expanded Register File Pointer

Working Register Pointer

R253 RP

Default Setting After Reset = 0000 0000

Figure 21. Register Pointer

The upper nibble of the register file address

provided by the register pointer specifies

the active working-register group

R253

I/O Ports

Specified Working

The lower nibble

of the register

file address

provided by the

instruction points

to the specified

R15 to R4

R3 to R0

R15 to R0

Z86L7208FSC Datasheet(PDF) 33 Page - Zilog, Inc.

Z86L7208FSC Datasheet(HTML) 33 Page - Zilog, Inc.

Html Pages

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71

Datasheet Download

Link URL