
MB91350A Series
12
(Continued)
Pin no.
Pin name
Circuit
type
Description
161
CS3
C
Chip select 3 output. This function is enabled when the chip select 3 output is en-
abled.
PA3
General purpose input/output port. This function is enabled when the chip select
3 output is disabled.
164
RDY
D
External ready input. The pin has this function when external ready input is en-
abled.
IN0
Input capture input pin. Since this input is used as required when selected as an
input capture input, the port output must remain off unless intentionally turned on.
P80
General purpose input/output port. This function is enabled when external ready
signal input is disabled.
165
BGRNT
D
Acknowledge output for external bus release. Outputs L when the external bus is
released. The pin has this function when output is enabled.
IN1
Input capture input pin. Since this input is used as required when selected as an
input capture input, the port output must remain off unless intentionally turned on.
P81
General purpose input/output port. This function is enabled when external bus re-
lease acknowledge output is disabled.
166
BRQ
D
External bus release request input. Input 1 to request release of the external bus.
The pin has this function when input is enabled.
IN2
Input capture input pin. Since this input is used as required when selected as an
input capture input, the port output must remain off unless intentionally turned on.
P82
General purpose input/output port. The pin has this function when the external
bus release request input is disabled.
167
RD
D
External bus read strobe output. It is available in the external bus mode.
P83
General purpose input/output port. This is enabled at single chip mode.
168
WR0
D
External bus write strobe output. It is available in the external bus mode.
P84
General purpose input/output port. This is enabled at single chip mode.
169
WR1
D
External bus write strobe output. This function is enabled when WR1 output is en-
abled in external bus mode.
IN3
Input capture input pin. Since this input is used as required when selected as an
input capture input, the port output must remain off unless intentionally turned on.
P85
General purpose input/output port. The pin has this function when the external
bus write-enable output is disabled.
170
SYSCLK
C
System clock output The pin has this function when system clock output is en-
abled. This outputs the same clock as the external bus operating frequency. (Out-
put halts in stop mode.)
P90
General purpose input/output port. The pin has this function when system clock
output is disabled.
171
P91
C
General purpose input/output port.