P90CL301BFH Datasheet, PDF (49/92 Pages) NXP Semiconductors – Low voltage 16-bit microcontroller

Philips Semiconductors
Low voltage 16-bit microcontroller
Preliminary specification
P90CL301BFH (C100)
12.5.1 I²C-BUS STATUS REGISTER (SSTA)
SSTA is an 8-bit read only Special Function Register. The contents of SSTA may be used as a vector to a service routine.
This optimizes response time of the software and consequently that of the I²C-bus. Tables 73 to 77 show the list of the
status codes defined by the contents of register SSTA.
Table 70 I²C-bus Status Register (address FFFF 8205H)
7
6
5
4
3
2
1
0
SC4
SC3
SC2
SC1
SC0
−
−
−
Table 71 Description of SSTA bits
BIT
7 to 3
2 to 0
SYMBOL
DESCRIPTION
SC4 to SC0 The bits SC4 to SC0 hold a status code.
−
Reserved; held LOW.
Table 72 Used abbreviations in the mode descriptions; see Tables 73 to 77
SYMBOL
SLA
R
W
ACK
ACKNOT
DATA
MST
SLV
TRX
REC
DESCRIPTION
7-bit slave address
read bit
write bit
acknowledgement (acknowledge bit = 0)
not acknowledge (acknowledge bit = 1)
8-bit (byte) to or from the I²C-bus
master
slave
transmitter
receiver
Table 73 Master transmitter (MST/TRX) mode
SSTA VALUE
08H
10H
18H
20H
28H
30H
38H
DESCRIPTION
A START condition has been transmitted
A repeated START condition has been transmitted
SLA and W have been transmitted, ACK has been received
SLA and W have been transmitted, ACKNOT received
DATA of S1DAT has been transmitted, ACK received
DATA of S1DAT has been transmitted, ACKNOT received
Arbitration lost in SLA, R/W or DATA
1996 Dec 11
49