Table A-10 U and V Field Definition

U0

V0

Definition

0

0

EF not supported in controller

0

1

Reserved (for a second alternate character mode)

1

0

Default Character Mode—start position 1

1

1

Alternate Character Mode—start position 1

Table A-11

Vector type V = 000

All Fragments

Message

i0

i1

i2

i3

i4

i5

i6

i7

i8

i9

i10

i11

i12

i13

i14

i15

i16

i17

i18

i19

i20

Word

1st

K0

K1

K2

K3

K4

K5

K6

K7

K8

K9

C0

F0

F1

N0

N1

N2

N3

N4

N5

s0

s1

2nd

a0

a1

a2

a3

a4

a5

a6

b0

b1

b2

b3

b4

b5

b6

c0

c1

c2

c3

c4

c5

c6

3rd

d0

d1

d2

d3

d4

d5

d6

e0

e1

e2

e3

e4

e5

e6

f0

f1

f2

f3

f4

f5

f6

4th

g0

g1

g2

g3

g4

g5

g6

h0

h1

h2

h3

h4

h5

h6

i0

i1

i2

i3

i4

i5

i6

5th

j0

j1

j2

j3

j4

j5

j6

k0

k1

k2

k3

k4

k5

k6

l0

l1

l2

l3

l4

l5

l6

...

nth

i

i

i

i

i

i

i

i

i

i

i

i

i

i

i

i

i

i

i

i

i

MOTOROLA

MC68175/D, Preliminary

A-13

Table A-12 Secure Message Bit Definitions

Symbol

Definition

K

10-bit Fragment Check Character—This check character is calculated by initializing

the fragment check character (K) to 0 and summing the information bits of each code

word in the message fragment (including control information and termination

characters and bits in the last message word) to a check sum register. The information

bits of each word are broken into three groups: the first is the 8 bits comprising i0

through i7, the second group comprises bits i8 through i15, and the third group

comprises bits i16 through i20. Bits i0, i8, and i16 are the LSBs of each group. The binary

sum is calculated, the one's complement of the sum is determined, and the ten LSBs of

the result is transmitted as the message check character.

C

1-bit Message Continued Flag—When set, the Message Continued Flag indicates

fragments of this message are to be expected in following frames. The longest message

that will fit into a frame is 84 code words total. Three alpha characters per word yields

a maximum message of 252 characters in a frame, assuming no other traffic. Messages

longer than this value must be sent as several fragments.

F

2-bit Message Fragment Number—This is a modulo 3 message fragment number that

is incremented by 1 in successive message fragments. Initial fragments start at 11 and

increment 1 for each successive fragment. The 11 state (after the start fragment) is

skipped in this process to avoid confusion with an initial fragment of a non-continued

message. The final fragment is indicated by Message Continued Flag being cleared.

N

Message Number—When the system supports message retrieval, the system

controller will assign message numbers (for each paging address separately) starting

at 0 and progressing up to a maximum of 63 in consecutive order. The actual

maximum roll over number is defined in the pager code plug to accommodate values

set in the system infrastructure. When message numbers are not received in order, the

subscriber should assume a message has been missed. The subscriber or the pager may

determine the missing message number(s) allowing a request to be made for retrieval.

When a normal unnumbered numeric message is received (message retrieval flag is

equal to 0), it is not to be included in the missed message calculation. This number is

also used to identify fragments of the same message. Multiple messages to the same

address must have separate message numbers.

s

Spare Bit—not used and set to 0

A-14

MC68175/D, Preliminary

MOTOROLA